Mate itself has not had a release since February of 2024. Sad to say, I think it's probably mostly dead. IMO, Mate held the crown for most usable Linux desktop during most of its existence, but development has slowed down to the point it is missing important features like fractional scaling. The good news is now KDE Plasma has gotten good enough that you can configure it to have the Mate layout and it is nearly strictly superior. If anyone is looking for an alternative, I would encourage you to try it.