We'll have to wait and see.
PayPal is working indeed with IOUs now (like Revolut does and I've didn't see such loud complains). But they have plans to connect with an exchange service and then I think that proper deposits and withdrawals will be possible.
However, PayPal doesn't seem to intend to ever use actual Bitcoin. But as long as a third party will do that on behalf of PayPal it should be fine, I think. If they won't then yes, we'll have a problem.