Your apple ID is now being used for iMessage and FaceTime on a new Mac

I manage multiple labs with approximately 100 computers. Computers are setup with multiple student accounts, depending on the class. Each time a user logs on, this message displays on the remaining computers. So, it's possible that the message will display for every computer logon. As you can imagine, it's annoying and time-consuming to close.

Since the message is tied to the department's AppleID, I can't change it. Is there a terminal command or script that I can execute to suppress this message?

Thanks in advance for any help.