Not A Bug PoK on Firiona Vie server missing anniversary NPCs

Firiona Vie server crashed and was restarted, but the anniversary NPCs are now missing from the Plane of Knowledge.

quess we cannt do anymore =/ lol

looks like they back now

When server crashes they do eventually return takes about an hour, had the same previous years.

It takes some time for spawns that are associated with events to pop after a zone comes up / is repopped.
This is not generally a problem after a patch, because the server is up for quite a while before it's unlocked, but it can happen after a zone / server restart when there's less or no delay on the zone coming up and characters logging in.