A lot of people say that they would've wanted to see sunset returning to equestria if we ever got some kind of closure,but i cannot dissagre more in that.
Sunset's arc has always been about finding a place in the world where she is now. Yes, she was in equestria once, but she left and altough was forgived by Celestia, I doubt the things would be the same between them. She already cut her relationships with most of the people back there (even her family) , and yes she has Princess twilight friendship and the mane 6, but im sure she wouldn't feel the same way with them like she does with earth mane 6 , as they don't have the exact same personalities and traits. I think she has grown enough to realize where she belongs, not needing of magic to make herself a name or friends.... the friendship games was supposed to touch in this topic but didn't ended up doing as far as I know..
So, in case they ever do a closure, i think she should finally face the dilemma of going back or staying in the human word, finally deciding to stay after realizing that this world has given her the best thing : her best friends. In her future, i see her moving from the city after graduating from canterlot high... I'll think before going to a college of some sorts (we know she is smart asf)I see her travelling the world, exploring the differences this world has to his once homeland equestria, and also searching around for Equestrian magic (we know is everywhere as seen in the spring episodes) ... acting kinda like a mediator between equestria and the other world... just some thoughts haha