Character select in during match

I want to show a widget during an online match and allow the player to select one of four classes to respawn with.
Would I just be re-possessing the character pawn with the current player controller? Any input is welcome.

Depends on how they differ and how you want to split the classes logically.
Do you want to put all 4 classes into a single character blueprint?

Because if it’s just the looks (if no game logic depends on it), you might just change the model or material on the character, not even bothering to spawn/repossess anything.

If they have different input styles and abilites, you probably want to have multiple character blueprints. In this case, you would destroy the old Pawn and possess the newly created pawn.

Personally, I would go for the later and introduce a parent pawn, from which they all extend (so common features can be shared easily).