Twiddle to see if overriding .on works

components.alert-pow.js

import Ember from 'ember';

export default Ember.Component.extend({
  powPow: function() {
    alert('POW POW POW!!!');
  }.on('didInsertElement')
});

components.pow-subclass.js

import AlertPowComponent from 'demo-app/components/alert-pow';

export default AlertPowComponent.extend({
  // overrides parent's .on
  powPow: function() {
    // noop
  }
});

templates.application.hbs

<h1>Welcome!</h1>
{{outlet}}

{{pow-subclass}}

twiddle.json

{
  "version": "0.4.11",
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/1.13.10/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/1.13.13/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/1.13.10/ember-template-compiler.js"
  }
}

conclusion: the subclassed method overrides the .on method