If you are trying to comply with GDPR or similar privacy legislation, the request does not need to be in any particular format. A request is a request.
For any other [that I can think of] it is at your discretion.
This isn’t a legal discussion though – it is a people discussion. @Jumanji I’m curious as to why you are on the fence about how to behave here. If someone asks you to remove their account, I would just remove it. If they change their mind, that’s on them. You don’t have to be accountable for that.
Yup, I’d do this. But when the deadline comes up, actually do it.
It sounds to me like this person is just struggling with their own boundaries. They want to leave but they kept getting sucked back in because technology can often become an addiction.