The British government is planning on giving up sovereignty over Chagos Islands, situated in the Indian Ocean. Once the deed is officially sealed and done, the British Indian Ocean Territory (BIOT) will cease to exist and International Standard Organization (ISO) will remove country code "IO" and websites will no longer be issued .io domain. Websites currently using the domain will have to look for new ones.

Chagos islands will be part of Mauritius (domain .mu):

So, itch.mu? itch.com? itch.net?

Edit: probably also worth mentioning that .io is a top level domain and simply the owners will change, but the domain stays.

References: 

2024 Oct 08 article on every.to by Gareth Edwards - https://every.to/p/the-disappearance-of-an-internet-domain

2024 Oct 03 article on reuters.com by Alistair Smout et al - https://www.reuters.com/world/britain-agrees-chagos-island-sovereignty-deal-with...