This is why you should be extremely wary of anything that is only run once in a a blue moon. And very wary of such things that when run, are being run to save your bacon.
If you don't need "high availability", then it will test your backups and restore process, and if you do need "high availability", it will ensure your failover processes are running smoothly.
Not to mention it trains everyone involved what to do in an emergency since it should be second nature by the time it really happens.
If you can't go "Full netflix" and unleash a chaos monkey on your servers, at least setup a maintenance period where downtime is somewhat expected, and do it then.
I find this similar to when you launch a project that hasn't been used in production yet. Bugs should be expected because it hasn't been battle tested.