If you send an e-mail to
forgedanvil.sheet@gmail.com you get an auto-reply with a downloadlink for the latest Xanathar Release version. (currently 2.28.03)
This contains the whole of Xanathar, many bugfixes and a working import from previous versions.
It also has overwrites for some class features like Sorcerer and Ki points and it shows more weapon info like offhand damage.
To me it seems it is way ahead of the development of "B4".
ForgedAnvil has been supersilent for months. The cease and desist we saw here was for Enworld but maybe he got one as well.
Maybe sometime he will "endorse" one of the multiple running projects, but until then you will have deal with "unofficial" releases if you want Xanathar and soon Mordenkainen.
PS. I'm not the creator of the Xanathar Release, but I know they read this thread, so feel free to ask questions and report issues.