“Rule 1-4-11-b is very specific and allows only voice communications between the press box and the team area, therefore in (a) the coach could not call into the press box or the sideline for anything related to coaching purposes.”
"Prohibited Field Equipment – Rule 1-4-11
Play #1: The Head Coach of the home team is in quarantine, and wants to monitor the
TV broadcast and (a) call in plays via cell phone to the offensive coordinator (b) use a
virtual application (Zoom, Microsoft Teams, etc.) to communicate with the team in the
locker room.
RULING: Rule 1-4-11-b is very specific and allows only voice communications between
the press box and the team area, therefore in (a) the coach could not call into the press
box or the sideline for anything related to coaching purposes.
Rule 1-4-11-a prohibits the use of technology including computers to be used for
coaching purposes and this would include all virtual types of communication back to a
team during the game, consequently in (b) any virtual session with the team would not
be allowed. This prohibition would begin at 90 minutes before the scheduled kickoff
when the officiating crew assumes jurisdiction of the game and would include the time
between periods until the end of the game when the Referee declares the score final."
This is why. It's a good rule. Brohm would have a huge advantage.