I think '.su' is already that precedent, since it had many active domains, recently had active registration, and ICANN has announced plans to phase it out.

https://en.wikipedia.org/wiki/.su

See also '.yu' and friends, which have already been deleted.

The fact that the country ceased to exist a year after .su was created and yet the TLD still exists 34 years later is probably precedent for the opposite.

How many domains are we talking though, and how many .io are there? Genuine question since I have no idea.