Black swan events affect non-digital information as well. How many paper records have been lost to fire, floods and simple decay over the millennia? At least with digital records there's the chance that they're backed up offsite somewhere
https://www.riigiteataja.ee/aktilisa/2280/3201/8002/Lux_Info...
This has been standard procedure (not at Svalbard, obviously, but at one or more secure offsite facilities) for every critical data system I’ve ever personally encountered in regulated industry, though rotations are usually weekly/monthly rather than yearly.
Are they testing the backups and restoring from them regularly, because if they aren't there isn't any backup happening.
But I don't blame you for asking, when there are stories of irreplaceable nuclear test data being stuffed on some RAIDs and then nobody replacing the disk failures for years and years...