Battlepass expiration shouldn't be a thing.
People no matter when they play, whether they just joined after first season or they gave a break for months. Battlepasses should not go away. But shown as a list to give users choice on which season's battlepass they want to progress towards freely.
Makes user more comfortable with game, making them spend more money while being happier about it.

(Also tell whoever purchased your studio that....
I am not gonna swear... "Stop it. Get some help."
Because I know you guys in SG1 days were quite good at this. Having to change to UE5 is never a dev based choice here.)