So it would hinge on there being a rule if there can be 2 letter tld that are not country specific. The common usage is, that for some 2 letter tld that country specific meaning is not existing. So at least this rule is pointless and should be adjusted.
Also, and probably the most important thing, who would inherit the "rights" to .io, if the country no longer exists. Since small countries seem to generate income by this, this is all about money. There are over a million .io domains, I read somewhere.
I expect a lot of squabbling about this, till it either becomes a "regular" tld or some people abuse their power to try to destroy it, because they could not benefit from it.
The regular is in quotes, because those tld that are not country codes or com or org are not really in use much. They exist, yeah, but does anyone regularly use one of those? Do they make up more than 1% of the internet traffic? I seriously doubt that.