But I bet the people working on those don’t say their employer unexpectedly “roped me into a production support on-call”.

If a role isn’t advertised as having responsibility outside regular office hours, bait and switching people into regularly working outside 9-5 type hours should not be allowed. And “not allowed” with serious enough financial teeth that companies right up to FAANG size would care, or at least that employees leaving/fired from bait and switching employment hours would end up feeling satisfied with their payouts.

If you need uptime guarantees, hire people letting them know up front so they can choose to accept or reject that work. You don’t (or at least shouldn’t) get to drop that responsibility on people who never signed up for it in the first place.