I think it's likely they'll annex, in some form, all of Eastern and Southern Ukraine to Odessa (Russian built that city from the first spade of dirt onward) and into Transwhatever.
They'd be crazy not to.
Okay, and what about all the Ukrainian families that have lived there for generations, and consider themselves loyal Ukrainians?
This sort of thing is best left as is. This comes up out of the blue and one side wants their views listened to. And then fifteen years later another side wants their listened to.
Leave things as they are.
Russia lived with this for several decades. They should have accepted it and moved on.