> ICANN’s policy on ccTLDs is pretty straightforward — your territory has to be on the ISO 3166 list and the ccTLD has to match the code ISO gives you. If your code drops off the list, you have five years, extensible to 10, to conduct an orderly transition before the TLD is retired.
Yeah, no, on the ISO 3166 list the soviet union is notably absent, and that country has been gone for over 30 years and yet, you can still buy a .su domain to this day if you wanted. ICANN considers the usage of the domains and how potentially damaging it could be to remove a domain, I strongly strongly believe that .io is here to stay.