I’ve noticed at least one instance (Marine Attack Squadron 231) in which what was previously a CAS squad, is able to equip a Fighter (The new P-38G). It still uses a CAS pilot (at least in this squad, I haven’t checked to see if it could be equipped elsewhere) but in-game, it functions as a Fighter and does not take up the CAS vehicle slot. I don’t really care if this is fixed or intended, but if it is left as is, it would be nice if there was some indication in the main menu menu of which vehicle slot the squad takes up (CAS or Fighter, each have a limit of 1 spawned at time in a match) to avoid player confusion.
The P-38 G from Normandy (that was available from the old campaign system) is considered as a fighter. The new P-38G that you will find in the tech tree is an attacker.
It could use more testing to be certain, but I am fairly sure that in-game, it is still considered a Fighter. Despite the fact that it is in a CAS squad.