After tracking a few playthroughs,
Emi, Lycanroc, Diane are always furry.
Isabella, Mil0 are always antifurry.
Renamon, Roxanne, Salazze, Nicole, Loona, Krystal, Neco-Arc Ralsei can be either.
Antifurs only kill the night after they enter the lab so if someone dies the same night then a antifur already was in the lab. Ralsei flew under my radar a few times since shes a sneaky one. also antifurs wont attack other antifurs so you could legit have only antifurs instead of all furs if you wanted.