A change should only be made if there are more story-telling oppertunitys with it than without,the wrighters have MORE than earned that trust guy's, this may been an editorial decision that they didn't have control over, but I feel they'll put our woories to rest once the first episode of season 4 gets hear!!!
Not if the writers handle it well. People were predicting doom for "A Canterlot Wedding" (another alicorn! Boo! Who are these bozos we've never heard of? It's just to sell those wedding toy sets!), and look how that turned out. It was an awesome finish to Season 2, with at least three great songs. Meghan McCarthy did a great job.
And now I've seen similar naysayers regarding "The Crystal Empire", which I'm sure is going to turn out amazing, also.
Just wait and see. MLPFiM hasn't disappointed yet, and I don't expect it to anytime soon.