I agree, and they have no homepage or anything either. Unity was (is) a desktop environment alternative to Gnome. It used to be the default in 16.x but Gnome became the default in 18.x.
Remix is (I think) an updated, forked version of Unity that is now being maintained and advanced with the latest versions of Ubuntu. This is particularly exciting for me and other Unity lovers because I pretty much only use Unity as my DE. I have been manually installing it as a replacement for Gnome and this update is very exciting. I think Unity is a lot better.