I don't think they ever changed the ending they just want to wait a few months to bring out the real endings so they can make more money by:
Getting alot of attention on it, so people who wondered why the game ending was so bad will buy the game.
Possibly making us pay for the true ending.
-Indoctrinated Theory-
So no they didn't react to the fans because they have had the real ending all along, they have just been biding their time.
Wrong, wrong, and wrong again.
- First of all there was no changes to the ending planned. When the fans started complaining BW had to scrap its actual DLC projects for now and focus on the Extended Cut...
- ...which is free...
- ...and does not change the ending, only adds cutscenes and perhaps edits the current ones. It's still the same nonsense as before but with less plot holes and cliffhanger.
The indoctrination is just fan fantasy built on denial and cherry picking, there is absolutely no reason to assume it has any credibility.