> ignore fsync and blatantly lie that the data has been persisted

Unfortunately they do: https://news.ycombinator.com/item?id=38371307

If the drives continue to have power, but the OS has crashed, will the drives persist the data once a certain amount of time has passed? Are datacenters set up to take advantage of this?

> will the drives persist the data once a certain amount of time has passed

Yes, otherwise those drives wouldn't work at all and would have a 100% warranty return rate. The reason they get away with it is that the misbehavior is only a problem in a specific edge-case (forgetting data written shortly before a power loss).

Yes, the drives are unaware of the OS state.