Sorting ember-data live array in route model hooks

in a ember route's model hook the following works fine:

model: function () {
    return this.modelFor('foo').get('bar');
}

Backed by ember-data, I can delete some of foo's bars somewhere else and it will be updated automagically (live array).

Now, I want this to be sorted (and user in sub-routes, so I have to do this in the route, not in the controller).

model: function () {
    return this.modelFor('foo').get('bar')
       .then(function (data) {
        return data.sortBy('baz');
    });
},

... does the job only the first time around, because I'm losing the updating.

Is there a way to write automatic updating sorting in line? What is the ember way to solve this?