Let me cook on this one ok?

So the theme for Camp Cataclysm’s roster is to bring calamity/destruction.

Alice is a demon, she literally warped reality of the school in Basics In Behavior animation, summoned spikes and more, so I think she fits into theme of destruction.

Pal Percy cause in the final boss fight he literally infected the whole place with those black wires.

Meaning that he's pretty powerfull and fits to the whole destruction theme of Camp Cataclysm's roster.

Morality, he's pretty horrifying looking and fitting to the game.

The Dog from Duck Season, he is pretty powerfull in his game, he can change sizes and more, so I think he fits to the whole theme of CC.

The Widow, the character itself fits to CC, just look at her design and tell me she doesn't fit.

Mick Mick aka Mother could fit but there is a problem, her design is to similar to current design of Mickey Mouse, but CC devs can redesign her and make Mick Mick look more like the version of Mickey Mouse that is in Public Domain right now.

Alice and Dog have a problem to, and it's permission, you see, CC devs have permission on every character that is going to be in the game, but creator of Dog is concerned about giving permissions on Dog to others, that's why Blade had to redesign Dog for PC 2, and creator of Alice left the internet, so adding them would be pretty difficult. But just like Blade, they can rename and redesign Dog. About Alice, creator of Alice left, but she update the bio on her channel saying that even if she will return, she no longer will make FPE stuff, that means that she no longer cares about FPE, cause if she did, she would've taken down a Roblox game called FPE: S by now.