Angular Material table not refreshed

<!DOCTYPE html>
<html>

  <head>
    <base href="." />
    <script type="text/javascript" charset="utf-8">
      window.AngularVersionForThisPlunker = 'latest'
    </script>
    <title>angular playground</title>
    <script src="https://unpkg.com/core-js@2.4.1/client/shim.min.js"></script>
    <script src="https://unpkg.com/zone.js/dist/zone.js"></script>
    <script src="https://unpkg.com/zone.js/dist/long-stack-trace-zone.js"></script>
    <script src="https://unpkg.com/reflect-metadata@0.1.3/Reflect.js"></script>
    <script src="https://unpkg.com/systemjs@0.19.31/dist/system.js"></script>
    <script src="config.js"></script>
    <script>
    System.import('app')
      .catch(console.error.bind(console));
  </script>
  <link href="https://rawgit.com/angular/material2-builds/master/prebuilt-themes/indigo-pink.css" rel="stylesheet">
  <style>body { font-family: Roboto, Arial, sans-serif; margin: 0 }</style>
  </head>

  <body>
    <app>loading...</app>
  </body>

</html>

var angularVersion;
if(window.AngularVersionForThisPlunker === 'latest'){
  angularVersion = ''; //picks up latest
}
else {
  angularVersion = '@' + window.AngularVersionForThisPlunker;
}
var materialVersion = '5.1.0';

System.config({
  //use typescript for compilation
  transpiler: 'typescript',
  //typescript compiler options
  typescriptOptions: {
    emitDecoratorMetadata: true
  },
  paths: {
    'npm:': 'https://unpkg.com/'
  },
  //map tells the System loader where to look for things
  map: {
    
    'app': './src',
    '@angular/core': 'npm:@angular/core'+ angularVersion + '/bundles/core.umd.js',
    '@angular/common': 'npm:@angular/common' + angularVersion + '/bundles/common.umd.js',
    '@angular/common/http': 'npm:@angular/common' + angularVersion + '/bundles/common-http.umd.js',
    '@angular/compiler': 'npm:@angular/compiler' + angularVersion  + '/bundles/compiler.umd.js',
    '@angular/platform-browser': 'npm:@angular/platform-browser' + angularVersion + '/bundles/platform-browser.umd.js',
    '@angular/platform-browser-dynamic': 'npm:@angular/platform-browser-dynamic' + angularVersion + '/bundles/platform-browser-dynamic.umd.js',
    '@angular/http': 'npm:@angular/http' + angularVersion + '/bundles/http.umd.js',
    '@angular/router': 'npm:@angular/router' + angularVersion +'/bundles/router.umd.js',
    '@angular/forms': 'npm:@angular/forms' + angularVersion + '/bundles/forms.umd.js',
    '@angular/animations': 'npm:@angular/animations' + angularVersion + '/bundles/animations.umd.js',
    '@angular/platform-browser/animations': 'npm:@angular/platform-browser' + angularVersion + '/bundles/platform-browser-animations.umd.js',
    '@angular/animations/browser': 'npm:@angular/animations' + angularVersion + '/bundles/animations-browser.umd.js',
    
    '@angular/core/testing': 'npm:@angular/core' + angularVersion + '/bundles/core-testing.umd.js',
    '@angular/common/testing': 'npm:@angular/common' + angularVersion + '/bundles/common-testing.umd.js',
    '@angular/common/http/testing': 'npm:@angular/common' + angularVersion + '/bundles/common-http-testing.umd.js',
    '@angular/compiler/testing': 'npm:@angular/compiler' + angularVersion + '/bundles/compiler-testing.umd.js',
    '@angular/platform-browser/testing': 'npm:@angular/platform-browser' + angularVersion + '/bundles/platform-browser-testing.umd.js',
    '@angular/platform-browser-dynamic/testing': 'npm:@angular/platform-browser-dynamic' + angularVersion + '/bundles/platform-browser-dynamic-testing.umd.js',
    '@angular/http/testing': 'npm:@angular/http' + angularVersion + '/bundles/http-testing.umd.js',
    '@angular/router/testing': 'npm:@angular/router' + angularVersion + '/bundles/router-testing.umd.js',
    'tslib': 'npm:tslib@1.6.1',
    'rxjs': 'npm:rxjs@5.5.2',
    'typescript': 'npm:typescript@2.2.1/lib/typescript.js',
    
    '@angular/cdk': 'https://npmcdn.com/@angular/cdk@'+ materialVersion + '/bundles/cdk.umd.js',

    // CDK Secondary entry points
    '@angular/cdk/a11y': 'https://npmcdn.com/@angular/cdk@'+ materialVersion + '/bundles/cdk-a11y.umd.js',
    '@angular/cdk/accordion': 'https://npmcdn.com/@angular/cdk@'+ materialVersion + '/bundles/cdk-accordion.umd.js',
    '@angular/cdk/bidi': 'https://npmcdn.com/@angular/cdk@'+ materialVersion + '/bundles/cdk-bidi.umd.js',
    '@angular/cdk/coercion': 'https://npmcdn.com/@angular/cdk@'+ materialVersion + '/bundles/cdk-coercion.umd.js',
    '@angular/cdk/keycodes': 'https://npmcdn.com/@angular/cdk@'+ materialVersion + '/bundles/cdk-keycodes.umd.js',
    '@angular/cdk/observers': 'https://npmcdn.com/@angular/cdk@'+ materialVersion + '/bundles/cdk-observers.umd.js',
    '@angular/cdk/platform': 'https://npmcdn.com/@angular/cdk@'+ materialVersion + '/bundles/cdk-platform.umd.min.js',
    '@angular/cdk/portal': 'https://npmcdn.com/@angular/cdk@'+ materialVersion + '/bundles/cdk-portal.umd.js',
    '@angular/cdk/rxjs': 'https://npmcdn.com/@angular/cdk@'+ materialVersion + '/bundles/cdk-rxjs.umd.js',
    '@angular/cdk/table': 'https://npmcdn.com/@angular/cdk@'+ materialVersion + '/bundles/cdk-table.umd.js',
    '@angular/cdk/testing': 'https://npmcdn.com/@angular/cdk@'+ materialVersion + '/bundles/cdk-testing.umd.js',
    '@angular/cdk/overlay': 'https://npmcdn.com/@angular/cdk@'+ materialVersion + '/bundles/cdk-overlay.umd.js',
    '@angular/cdk/scrolling': 'https://npmcdn.com/@angular/cdk@'+ materialVersion + '/bundles/cdk-scrolling.umd.js',
    '@angular/cdk/collections': 'https://npmcdn.com/@angular/cdk@'+ materialVersion + '/bundles/cdk-collections.umd.js',
    '@angular/cdk/stepper': 'https://npmcdn.com/@angular/cdk@'+ materialVersion + '/bundles/cdk-stepper.umd.js',
    '@angular/cdk/layout': 'https://npmcdn.com/@angular/cdk@'+ materialVersion + '/bundles/cdk-layout.umd.js',
    
    '@angular/material': 'https://npmcdn.com/@angular/material@'+ materialVersion + '/bundles/material.umd.js'
  },
  //packages defines our app package
  packages: {
    app: {
      main: './main.ts',
      defaultExtension: 'ts'
    },
    rxjs: {
      defaultExtension: 'js'
    }
  }
});

import {Injectable, Component, NgModule, OnInit, OnChanges, Input} from '@angular/core';
import {BrowserAnimationsModule} from '@angular/platform-browser/animations';

import {MatTableModule, MatTableDataSource} from '@angular/material';

import {BehaviorSubject} from 'rxjs/BehaviorSubject';
import 'rxjs/add/operator/delay';

class Person {
  constructor(public name?: string, public age?: number) {
  }
}

@Injectable()
export class PersonService {
  getPersonList() {
    return new BehaviorSubject<Person[]>([
      new Person('Mark', 15),
      new Person('Brad', 40)
    ]).asObservable().delay(1000);
  }
}

@Component({
  selector: 'app-person-list',
  template: `
    <mat-table #table [dataSource]="dataSource">
      <ng-container matColumnDef="name">
        <mat-header-cell *matHeaderCellDef> Name </mat-header-cell>
        <mat-cell *matCellDef="let person">{{ person.name }}</mat-cell>
      </ng-container>
      <ng-container matColumnDef="age">
        <mat-header-cell *matHeaderCellDef> Age </mat-header-cell>
        <mat-cell *matCellDef="let person">{{ person.age }}</mat-cell>
      </ng-container>
    
      <mat-header-row *matHeaderRowDef="displayedColumns"></mat-header-row>
      <mat-row *matRowDef="let row; columns: displayedColumns;"></mat-row>
    </mat-table>
  `
})
export class PersonListComponent implements OnInit, OnChanges {
  @Input() data: Person[];

  displayedColumns = ['name', 'age'];
  dataSource = new MatTableDataSource<Person>();

  ngOnInit() {
    this.dataSource.data = this.data;
  }

  ngOnChanges(changes) {
    console.log('Data changed', this.data);
  }
}

@Component({
  selector: 'app',
  template: `<app-person-list [data]="personList"></app-person-list>`
})
export class AppComponent implements OnInit {
  personList: Person[] = [];
  
  constructor(private service: PersonService) {
  }

  ngOnInit() {
    this.service.getPersonList().subscribe(res => this.personList.push(...res));
  }
}

@NgModule({
  imports: [BrowserAnimationsModule, MatTableModule],
  declarations: [AppComponent, PersonListComponent],
  bootstrap: [AppComponent],
  providers: [PersonService]
})
export class AppModule {}

//main entry point
import {platformBrowserDynamic} from '@angular/platform-browser-dynamic';
import {AppModule} from './app';

platformBrowserDynamic().bootstrapModule(AppModule)