.io will cease to exist as a ccTLD, but it doesn't mean it can't exist as commercial TLD like .app, considering its widespread use. I think eventually it will be auctioned off.
According to current rules, it can't. Only ccTLDs have two letters.
As the article says, money talks.
time to change the rules
TIL that .co is for Colombia. Goddam. I was about to buy a .co domain. I guess I'll have to shell out an extra $50k for .com just in case any more geopolotics happens in my lifetime :/