Not that I have seen. I think it's probably taking a long time and they don't have their full resources working on it cause it's a lot of work that they can't monetise. It will probably be one huge update once they have all the necessary changes ready.
minette and friends! finally thoses non playable characters can get some actionThe Skullgirls 12th Anniversary tweet for anyone who may not have seen it:
Mainly sharing this here because this is the first official mention of Valentine's visual update we've seen/heard in a while (as far as I'm aware).