Assuming there will be more content released for BG3, new playable subclasses (and MAYBE even one race or two) is pretty much one of the first additions I would expect to show up, yeah.
Way more likely than the "complete revamp of the Upper City" many keep begging for, at least.
Which on a personal level I don't think it's going to ever happen (but I DO expect to see some minor additions and tweaks to Act 2 and 3, in general).
I would like to see more classes.
That being said, I think it may have to wait for an expansion pack for that to happen.
