New Twiddle

components.my-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  a: Ember.inject.service(),
  
  willDestroyElement() {
    setTimeout(() => {
      alert(`Component isDestroyed: ${this.isDestroyed}`);
      alert(`service.title: ${this.get('a').title}`);
    }, 1000)
  }
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  show: true,
  appName: 'Ember Twiddle',
  
  actions: {
    hide() {
      this.set('show', false);
    }
  }
});

services.a.js

import Ember from 'ember';

export default Ember.Service.extend({
  title: 'asdasd'

});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
{{#if show}}
  {{my-component}}

  <button onclick={{action 'hide'}}>Destroy</button>
{{/if}}

<br>
<br>

templates.components.my-component.hbs

I'm Alive!

{{yield}}

twiddle.json

{
  "version": "0.15.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.2.2",
    "ember-template-compiler": "3.2.2",
    "ember-testing": "3.2.2"
  },
  "addons": {
    "ember-data": "3.2.0"
  }
}