Yes, the rumor is UG's former owners sold to Alta who recently had an investor call. Before that call they purged anyone and anything, regardless of how long it has been on the boards which they deemed a potential problem as they were looking for money to merge the UG with their MMA gym business and use it to mine sign ups. In the process, someone at the company also doxxed every user by putting their real name beneath their username. No idea if it was intentional or not.
I never really cared for the UG, but it's been around forever, and is a part of MMA history online before reddit, FB and discord came into the fray, just like the Dawg. Long live Suredawg.