They won't give Joe a callsign. He is not recognized by military as POTUS. They won't let him in Pentagon. That plane has not registered callsign AF1 since Jan. 20, last time Trump stepped off of it.
To add to your query…
Callsign is not subject to aircraft (AF1, AF2) but it is dependent on the passenger. Potus quite often flew on 757 (smaller jet) which registered AF1 only when he is on board.
Again Bidan is not relevant.
No, you're mistaken. I physically follow these planes religiously and especially while Trump was on them. I watched it with mine own eyes registered as AF1 on January 20th when Trump stepped off of it for the last time. Unless it is different plane but don't think so, it has same tail numbers.
OK. I digress