Objection!
This is the form to fill in to object
https://www.facebook.com/help/contact/6359191084165019
*HOWEVER*
Even when saying they'll respect the request their response, imho belies the fact they've already grabbed everything they want and anything already learned cannot be 'unlearned'.
Here's their response:
"We’ve reviewed your request and will honor your objection. This means your request will be applied going forward.
If you want to learn more about generative AI, and our privacy work in this new space, please review the information we have in Privacy Center.
facebook.com/privacy/genai"
Note the key phrasing "This means your request will be applied going forward."
They aren't to be trusted, going forward or backward for that matter.