You wouldn’t want to eat an animal that’s died of natural causes, it’s usually old and tough, or still died of an undiagnosed infection while old so not further investigated.

All meat sold for human consumption must be certified, not gonna happen with random dead zoo animals in any developed country.

If the zoo staff decide to go for it without, that’s probably on them, but they can’t sell or even legally give it away.

Ostrich is quite nice though, it’s a very lean, red meat. Like a gamey beef I’d say, but not as intense as deer.