ember model.get('elements.content.content') in setupController?

I'm trying to update an ember 1.7 app. In setupController() of a route

this.controllerFor('editor/object-list').set('model', model.get('elements.content.content'));

gets called, and element.content.content seems to return an array of models. in 1.10 it returns undefined.

elements and elements.content return <DS.PromiseManyArray:ember748> and <DS.ManyArray:ember749>, but elements.content in 1.10 has no content property. In 1.7 it does. Instead 1.10 has canonicalState/currentState properties that seem to hold the data that is desired. I don't understand why this was even done this way. Does someone have an idea?