I am positive seasons 1-3 would be the same intro as the canon one from that era, but anyone wanna pitch ideas for how the intro changes in season 4 and onward would work in this version?

I do imagine at least Sunset would be in the group shot in the end starting in season 4 intro, initially shown as a unicorn (to not spoil her becoming an alicorn ascension at the end of Princess Twilight Sparkle Part 2) in season 4 and then alicorn from season 5 intros onward.

Trixie would also get added to the final group shot starting with the season 7 intro.

7911913
Yeah. I could certainly see that. Of course, the intros would be entirely in our own heads anyway, but it IS a good thought exercise.

7911913
Of course, there would be other hypothetical intro changes: Given Caramel's somewhat expanded role, there could be some bits with him hugging Applejack in the early seasons and playing slightly bigger parts in the intro in later seasons. Flash Sentry would also be included in the intro Season 5 onward, signifying how close he and Twilight are getting. Button Mash could also be included having some cute scenes with Sweetie Belle Season 4 onward. And, of course, other characters as their roles start expanding.

7912039
Good ideas.