I had that event pop, and no skeletons appeared. I later found them clumped up in the water underneath my longship floating near my base. Literally like 20 of them in a moshpit under the boat.

Fun note; one of the only ways to find Rancid Remains other than dungeons

they can get distracted by something else and attack it; wander around after the event ends
and you'll find their remains and maybe what distracted them

No, I looked for them, but in vain, it is a large meadow around my camp and I would have necessarily seen them. I just got the name of the event and nothing else, I have more than 1600 hours of play behind me, I know the events but this is a first...bug???

skeletons love to chase boar,deer and greydwarves.
You'll find out if events are bugged somehow if your next raid is 'no event'.

Do know that somewhere there are skeletons and they will stick around until you kill them. I went out a week game time after a ekele event I ignored and there was carnage everywhere and a pack of them still running around. Great really, lots of loot. Same with draugrs, smell of swamp. They hang out indefinitely.

This might be wrong, but my expirence.

Event creatures spawn outside your area - i.e. outside any workstation area. They then come towards you. I've a big base, surrounded by large earthen walls, meaning no non flying creature can get in.

It does mean they can congregate somewhere outside your walls - might be some little crevice where you find all of them bunched up.

Oddly, it seems they are indefinite as someone said above.