it might help to think about this aistudio warning that has consumed your days as being like the confirmation they show when you delete a youtube video. to my eyes, these are consumer warnings positioned to be "extra scary" to consumers/users, not anything related to data retention.

they probably do not immediately purge your personal video bits upon YT delete either (i mean, who knows, but they can probably afford the space).

in fact, one could argue that being able to retrieve a supposedly destroyed "personal item" for no cost as being a benefit to the consumer/user, but i understand if that is a bridge too far.