Those that were banned, were they banned bcos they involved with yobit bounty? it's possible they were banned because of another offence i don't believe it's bcos they promoted yobit.
is not prohibition done for a certain period of time. if now I think everything can be recovered. the situation at that time did make a lot of people spam in the forum even though not all but I think there will be more than those who spam because there are people who post up to 10 posts every day. and the ban has also been issued, forum users should also obey it.