Just Isabelle, and a new mode. Modes are my favorite things that are added. There is only so much you can change with a new map, class, or cosmetics.
Please focus on modes like Predator v Predator ( With actually Predator melee system and maybe multiple Predators.)
Or obviously two or three predators vs multiply Fire-Team members. (You will need to extremely nerf FT damage, and gear.
TLDR: Focus on modes to really change it up, and make the modes that the community asks for.