One or two times past, an Xcode version around the time of a new OS release has been a problem on the older OS.
I don't see anything likely to be that way with Xcode 12.2 (and MacPorts) on Catalina, but I'm looking for alternative opinions; reverting is a nuisance. I'm in no hurry for Big Sur at this point; maybe I'll wait for the .1 or .2 of it, unless a compelling reason to update emerges.
