Consent during a sex act and consent to an image that you created continuing to exist after you knowingly release it into the wild are two different things. (Not including revenge porn or other nonconsensual recordings, obviously).

An actor who performs in an embarrassingly bad movie might wish they could refuse to let their work be used after the fact, but they already signed away their right to retract their work.

An OnlyFans model is also the creator of the content though, so they might have more leverage depending on OF's legal terms. If they still own the rights to all media they create and distribute through OF, then they could petition for removal based on DMCA or something (I'm not a lawyer but it sounds plausible).

Morally, I hope FB can help regretful adult models remove content of themselves if they don't want it to exist anymore. But practically, that will be very difficult to guarantee.

During the act, yes. But I think the example here is basically: In your 20s you did some jobs as a porn star. 5 years later you want the videos scrubbed from the web. Is this within your rights?

That's what OnlyFans images are.

The platform can stop hosting some content immediately once consent is withdrawn, but it can't prevent that content from having already escaped.

It's probably not technically a "gray area" since the platform can't ensure the content doesn't escape. But certainly, content creators should be aware that withdrawing consent doesn't mean their content is suddenly secured.

Consent? Yes. Images? No.

Any time? Can you withdraw consent after the fact and claim rape? If you are going to use categorical language, please be more careful about the language you use to describe a black and white world.