One thing that bothers me is this: if the leak really had something to do with the changing of the endings, it was a stupid idea. Leaks are bad, and obviously, spoil some of the surprise. But it does not, absolutely not, take away the virtue of a great ending!
If part of the surprise effect was diminished, why not just change details, or work on improving the endings or adding to it? Why throw it all away and start from scratch?
Again, a virtuous ending (good, solid storytelling, with the ending the characters and customers deserved) is a virtuous ending. No matter if it was leaked or part of it was.
The one thing you should refrain from doing is changing it completely, just for the sake of it. And sadly, it appears to have been the chosen course of action.