On the page of
unavailable moves, Serebii may just be listing all moves that do not appear in a legitimate learnset, and the message at the top of the page claiming you can't use the move in game may be an error (or maybe Serebii doesn't care about the distinction here because the moves would need to be hacked onto a mon). If you go to the actual move page for, e.g.,
Spectral Thief or
Meteor Assault, which are not on the
list of removed moves from the
Datamine thread, they have all of their data there (including new flags for Wind, sharp move), whereas if you go to the page of a removed move like
Barrier it lists the "this move cannot be used" text.
It could currently be unusable at the moment, but it seems like it hasn't been snapped.