It may possibly have been internally known for longer, but if not wasn't it only annouced publicly earlier this week? While the squad has some good riders, I think it would probably take longer than 4 or 5 days for agents to make teams get their cheque book out.
It was only announced publicly rather recently. However, even if it hadn't been internally known, there might have been a general sense of knowing where things were heading.
And it would still have been possible for riders, whose constracs were expiring anyway, to have signed new contracts regardless of the situation on the team.