I hope Opaline Arcana will return.

If Opaline returns I'd like to think it'll be as a defeated villain, not trying to take over nor being reformed (like I think Allura will be), just wandering and being done with it all since her arc is over. Kinda like the Sirens in EqG I was thinking when they showed up again in Sunset's Backstage Pass. And I think the next CG pony show will be called something else but if fans wanna call it MYM Chapter 7 that's ok.

It was already confirmed that MYM has ended but TYT is still continuing. IF they did come back, I'd like to see proper development with Sunny's Character with or without Opaline.

0:29 You're not legally step-siblings until the two parents get married but if they do, Alpha Bittle and Haven will be the only married couple in Equestria. Seriously, Sunny was the only one with both parents and she lost them both off screen.

Idk if your joking ngl, but given how Discovery Family will lose MLP and Hasbro shows MYM returning is kinda a possibility

Sorry hon, the last we saw of Opaline's castle in TYT the tree that k!lled her was gone. Now MAYBE the animators are as incompetent as the writers or maybe the tree ceased to exist and took Opaline's @$$ with it. Who knows?