RftLW mentions the mystic class?

[Millstone85]

I just read RftLW's description of the continent of Sarlona, and two sentences surprised me:
[Kasshta Keep]'s inhabitants include wizards, monks, and mystics
The Dreaming Dark is an enigmatic order of monks, assassins, warlocks, and mystics.

This seems indicative that the mystic class is still on its way, and under that name too.

[P. G. Macer]

Interesting catch. I wouldn’t put too much weight on this, as there’s still plenty of room for a copout on the developers’ part, but as IIRC psionic were an integral part of 3.5 Eberron, so WotC likely wants to keep the door open for now. It’s also possible they’ll errata it to the class’s final name later, though.

[Arkhios]

Yeah, don't read too much into it.
There are other editorial mistakes that were unnoticed before the book went to print.

One of the glaring mistakes which they've admitted already is that on one hand, in the description of half-orcs it says both orcs or humans associated with House Tharask cannot develop the Mark of Finding (which is inaccurate), but on the other hand, the description of Mark of Finding it says both humans and half-orcs can (which is accurate)

[Telwar]

That would be nice. I won't hold my breath, but psychic wizard just doesn't cut it for me.