I don't think that this was the correct way for them to approach it. They should have emailed all users and contacted them on all possible platforms, as opposed to just putting up an announcement as Bountyhonter said.

Furthermore, they should clarify what is going to happen after the withdrawal period ends. I don't think that 2 months is long enough, first of all, and they should at the very least have manual withdrawals after that period.

Otherwise, it's not fair to their users, or people who have small balances on there who may not know about it.