yes because at the time they didn’t know what to do, and gave .su to the .ru guys. For .yu it was also a little bit messy with multiple new countries wanting to control it. This is when IANA made laws to properly handle end of ccTLD like this, .yu does not exist anymore, it will be the same for .io
Yes, there is laws, IANA says that ideally in 3-5 years all the .io will be gone, like the .yu ones, they do not exist anymore.
The .su domain is still active and the Soviet Union does not exist for more than 30 years now.
yes because at the time they didn’t know what to do, and gave .su to the .ru guys. For .yu it was also a little bit messy with multiple new countries wanting to control it. This is when IANA made laws to properly handle end of ccTLD like this, .yu does not exist anymore, it will be the same for .io
https://www.iana.org/domains/root/db/su.html
https://www.iana.org/domains/root/db/yu.html