This is not typical - definitely write in.

Normally the cabin crew will take main meal orders before departure on the ground, or shortly after takeoff (depending on flight length and departure time). It's at this point that you're usually asked when you'd like to eat, and the crew will reserve dishes accordingly.

There has always been priority boarding for First, even at the height of the pandemic. If you miss the call for First or Group 1 (depending on whether the gate agents have got the memo about returning to group boarding), just approach the desk (bypassing any queue), show your BP, and you'll more than likely be waved through.