Most of this is non-canon. I took names from the MM2 for demon lords/etc., but the genealogy is all mine. Some of the versions of the demons (in particular Alrunes and Gresil) are heavily inspired by Allen Ruch's work, my old DM from my college days at Penn State.
The MotP will help you some, certainly, but doesn't really delve into the depths of Ayssal politics/history/etc. in the same manner that I do. If you're curious for more, some of my other articles in the Demonomicon series detail my visions for the lower planes:
