I’m not sure if this is intended or just a glitch but it doesn’t seem like something that shouldn’t happen. When I have my Spartan control one of my Kodiaks if I try to lock it down(which it needs to do before I can attack) my Spartan just pops out. I’m not sure if this is the Same when using other vehicle Y abilities, I haven’t them yet.
I like the idea that you can take your Spartan out of vehicles without destroying them but it shouldn’t replace the vehicle’s Y ability.