I'm not entirely sure what happened. I was fooling around with an Aeotec Micro Switch G2 that has always been problematic dropping off my network and needing to be power cycled. A power cycle didn't work, so I tried to exclude and include it (neither of which worked, either). And then, shockingly, all my Z-Wave devices disappeared from the Z-Wave settings page at <my.ip>/hub/zwaveInfo. (For the record, I definitely DID NOT reset the radio by clicking the red button)
I tried a soft reset and restore, but that didn't bring my devices back.