You're right that he doesn't plainly confirm it, sorry for my wording. However the explanation and actions taken are both good indicators that they have a high enough level of confidence to say that B should have no business posting to Q's private board, that B won't be posting in the future, and that we should not give B any further attention.

Besides none of the Q archives have added B anyway, and they have a better idea than we do (maybe even more direct lines communication) about the workings of 8kun and the /qresearch board, and which account of Q is the real deal.