Now I'm picturing a pack of bratwurst with a built-in USB-powered heater... I guess that would be "USB-C brick o' brats" though.

Review by overworked, underpaid, miserable sweatshop contractors forced to work as quickly as possible, who will take shortcuts at any chance... that's not much of a safety net. Look at the "quality" of human reviews done by eg YouTube for videos that get falsely reported or which are automatically flagged for some kind of violation. There are countless stories of human reviewers agreeing with accusations that are immediately, obviously, objectively blatantly false.

Also, since it's possible to modify an arbitrary image to match a given has, an attacker just needs to do the modifications to images that a human reviewer might confuse for CP... eg, lawful porn images. A human reviewer presented such images, especially with blurred versions, will have difficulty telling that they're not actual CP.

A metaverse run by Facebook sounds like a nightmare cross between The Matrix, 1984, and a world with advertising and manipulation so pervasive it could make the stuff portrayed in the likes of Bladerunner/Minority Report/Ready Player One/etc seem tame by comparison.