Haven't read the thread or followed Psionicsgate closely, but it really seems like there's no point in adding--and calling it--"psionics" if it is just more spells, albeit of a psychic nature. Why not just add psychic-flavored spells to wizards or, better yet, sorcerers?
On the other hand, a multi-faceted approached could be taken, each as rules options:
*A "mind mage" wizard and/or sorcerer sub-class (this is the easy but blandest route they seem to be taking with Tasha's).
*A "mystic" or psion new class, with an entirely different sub-system that makes psionics feel and play differently.
*A AD&D style sub-system in which PCs of any and all classes can have "psychic abilities."
So there you have it: mind mage, mystic/psion, and psychic abilities. Best of all worlds, and all optional.
I am honestly baffled why it has been so hard for WotC to figure this out. These folks do game design as a full-time vocation. I know you can't please everyone all of the time, but there does seem to be general consensus that psionics should look and feel differently than other forms of supernatural power. To quote the Great French One, "Make It So."