The channel has been renamed as "RMC - The Cave" at least two or three years ago. Neil was already shortening the channel name into RMC in his videos, so to him this was a fairly easy decision to make. The main reason to do the change in the first place, is that the "Man Cave" part was originally a joke from his wife (a sign above the door to his hobby space) and not entirely fitting a channel that is now made (semi)-professionally in a space outside the house. He even has a computing museum nowadays so he wants to do all this without jokes that could be misinterpreted without context.