The point of verification photos is to ensure that nsfw subreddits are only posting with consent. Many posts were just random nudes someone found, in which the subject was not ok with having them posted.

The verification photos show an intention to upload to the sub. A former partner wanting to upload revenge porn would not have access to a verification photo. They often require the paper be crumpled to make it infeasible to photoshop.

If an AI can generate a photorealistic verification picture, it cannot be used to verify anything.