Its Hasbro. They made Star Wars action figures based on characters that I still have to have pointed out on the screen to find. It would not surprise me if they are just trying to cash in on a “it was all just a dream”-esce sequence. If my memory serves me correctly they made a Rarity toy with butterfly wings, which was certainly not permanent
It certainly is possible for it to move towards a more developmental continuity. However, I think Hasbro originally didn’t like the idea, and so the show went the way it did. Things may have changed since then though. We’ll just have to see.
As for “what if”, what do you mean by this exactly? Are you asking our personal opinions on the subject (it will somehow “ruin” the show or make the show better), or more of the over analytic type of how the new addition to the equestrial pantheon works out in this world? Or, alternatively how the show will handle it?
In Regards to that last part… Both.
How would Twilight Sparkle staying an Alicorn affect the fandom?
How would it affect the world of MLP?
The questions are inter-related.
Personally, I err on the mildly positive in case of how I’d take it. I have no idea how the others would take it.
As for the world. I don’t know… I really don’t.
Edit: I had no idea until you said so, that Hasbro did all that. /Shrug. I still think It’s got a possibility of confussing those who don’t see the episode. Rarity less so since fairy ponies havn’t been shown outside of her. But with Twilight I suspect the reaction of kids would be “but Twilight doesn’t have Wings!” since… Well… Winged unicorns already exist.
But then again, from what you say about Hasbro, they aren’t concerned with confusion with merchandise.