The thing is that until an account is fully deleted, it could be reactivated. If we would let you delete your client area profile before the account is deleted, there is the risk the account could be reactivated. And then we have an active website for which we have no records in our systems, and have no idea who owned it or what happened to it.
So you have to wait for all hosting accounts to be completely deleted. After that, you can delete your client area profile, and all data will be removed.