Servers will be updated as they 30k and shutdown. To know if you join a server with the fix, check the server version with: r_displayinfo 2
Hotfixed servers will appear as 8478820-8520604

Edit - Info comes from the MOTD:

(Tysdagr) We are not expecting a new PTU publish today. We are rolling out a client and server hotfix onto the LIVE environment to address unusable/black screen ASOP issues! This is a 2 part hotfix which requires both pieces to fix. You will see a small client update shortly but the LIVE servers will be gracefully hotfixed over time as old servers crash out and new servers spin up so it may take a while for all servers to get it. (server hotfix 8478820-8520604)