Precociously, and already utilised in other regions already.
However, when 5g wifi first came about, many weather radars had issues and DFS was born, compulsory in some countries and is designed to make sharing bandwidth less impacting. So historically, there may be some jitter in some regions and more so for regions like the USA that would of utilised that spectrum differently and with that, the impact may well be deeper and like most change - people will always have concerns, however long they are given before that change.
It's odd, I remember the Department of Defense complaining about the L-band auction back in April[0] but I don't see anything about them opposing C-band auction.
