When does it become mathematically impossible to all the panicked doubters?
Guess who's back.
The ban page on 8kun does indeed show that the B post was removed and blocked from projectdcomms by the actual board owner 2 days ago.
Assuming the ban page hasn't been messed with, that means whoever removed the post did it with Q's password.
Assuming Q was smart enough to have separate passwords for his tripcode and his private board, that would mean that any potential hacker would have to crack two separate passwords in order to pretend to be Q.