@mttaggart @mwl The article also outlined cases in which their rules were not abided for decades.

The IANA may decide to act against their rules if it is in contrast with their mission statement "[..] maintaining the trust of the community to provide these services in an unbiased, responsible and effective manner". You could say that It would be irresponsible to shut down .io after it had been widely adopted for other purposes. They may also reclassify .io from a country-code to a generic code instead.
The outcome is not clear.