Facebook is just dying and they know that from their internal metrics long time now so these features have been developed to save the engagement because otherwise facebook's stock value will plange.
Yes Ember-Data was great thing to have in Ember, something I miss from React ecosystem. In the early days was a bit unstable but now it's super stable and flexible (serializers/adapters customization etc). I think there should be an initiative to get it out of Ember so that you can use it with other projects as well.