As with many other subreddits, /r/LegalAdviceUK (which had been dark since the start of the blackout) has been sent a thinly-veiled threat by Reddit.
So they’ve reopened in order to start moving the entire community of 810,000 subscribers to somewhere else.
As you can imagine there are a number of legal professionals who moderate that sub, and they really don’t take kindly to being threatened. They sign off their reopening message with “Fuck /u/Spez and long live John Oliver.” but for the real fun you might want to look up a very famous British legal case they reference, Arkell v Pressdram 1971.
Guilded is also owned by Roblox, which has its own troubled history. If r/legaladviceuk wanted to go the chatroom route, it’d probably be better to go to a FOSS alternative like Revolt, Matrix, or Signal.