I don't think "banned" is the right word because Meta chose not to release the app until they've cleared the account sharing. They're just being cautious.
It doesn't seem to me that logging in to your account from multiple apps should be a GDPR issue. Lots of companies have that kind of setup where they offer separate mobile apps for different user roles.
Are we going to go back to country specific social networks like Orkut? VK? (which is still going)