When it comes to regulatory and tax regimes countries are in competition with each other. If countries undercut the shit out of each other to get Apple's billions, they're really not going to let up to get a piece of potential crypto trillions.
If something like this was ever managed, somewhere like Vanuatu could drop out and instantly double its GDP.
If there is a universal ban on cryptocurrencies or regulations not very far from it established and enforced by major governments, Vanuatu and similar micronations won't have a say in the matter. These regions will soon be declared safe havens for terrorists, pirates, slavers, drug traffickers, whatever, and they will have to face the consequences. Just like it happened in Iraq.