Has no one here played Warzone before? every year the devs really do go all fucking out on their halloween theme. I remember zombie matches where if you died you just became a zombie and if you kill a player or two you get revived, and another that was ghost themed and then there's the krampus events during christmas and other silly holiday bullshit. the 1980s themed even during cold war was so good they brought them back in the tail end of cold war under a new name because of how beloved they were, Going all out on slashers would be neat too.
Another thing is that they literally will do stuff like change the usually daytime warzone into an all night map which is an insane amount of work for something you'll use one month in the entire lifetime of the game. Warzone in general seems to put way fucking more into their holiday events than any other game especially fortnite, i'd say the same with seasons honestly. fortnite seems way less into change whereas call of duty is pretty good on changing shit up for next to no reason and making it feel like different and give you a reason to come back again.
COD going full slasher wouldn't surprise me. their krampus events is pretty much that with extra steps. having dozens of those fuckers running all over probably wouldn't even be that difficult considering all the bots they used in warzone to annoy the shit out of players.