> But they did load-shed

Right, exactly, I highly doubt the facility went into any kind of actual uncontrolled thermal rise. This is news because they had to take such drastic actions. I'm sure its common that they force spot prices up (probably way up) to compensate for reduced capacity due to events, I'm sure they even sometimes fake no capacity for similar reasons. No capacity means "I don't want to turn on your node" not merely "I don't have any more physical servers I could turn up for you".

This is news because they powered off some non-preemptible customer loads, which actually makes me wonder if you saw that chain of events occur here.

spot prices rise -> new instance availability goes to 0 -> preemptible instances go dark -> normal instances go dark.