It's possible that the .io cctld is going to go away [0]. Does crates.io have a backup plan at all? Does anyone know what problems it would end up causing?
I imagine the package registry having to move domains is going to cause a ton of problems.
Frankly, it's concerning to me that so much of the Rust ecosystem has chosen to standardize on shaky ccTLDs. The Indian Ocean Territory (.io) is a small island territory whose only inhabitants are a single military base, it is crazy to use that domain for something important. Serbia (.rs) is more stable, but they could still cut off access for non-Serbians if they wanted to.
[0] - https://en.wikipedia.org/wiki/.io#Phasing_Out
It shouldn't be too hard to have a backup domain point to the same resources. Could even be setup as a fallback mirror by default.