Just putting it out there that I have had this error too. The wolves are released and come running though my village. Then they they just despawn at a point on the other side of the village, ignoring the village and the villagers.
If you mean they were released from their cage by a hearthling destroying it, then that it was is supposed to happen. If that’s not what you meant, then yeah it’s a bug.
This isn’t actually a bug as you mean it. Enemies despawn after a given amount of time for performance reasons. The wolves don’t attack unless provoked so what probably happened here is that you provoked them just as they were about to despawn giving the impression that they dissappeared as you went to engage.
The despawning of enemies will probably be able to be removed with the introduction of Chris’ topography service in Alpha 21/22.
I had the goblin village spawn, the one that has the pen of wolves in it. After a short time those wolves were set loose onto my village by the goblins, not provoked. The wolves then ran through my village from one end to the other, didn’t touch or pay any attention to any of my villagers, even the footman that attacked one. Once they got to the other side of the village, they despawned. If actually happened twice, but the second time I think I provoked them, however they still ran through the village and despawned on the other side.
If it’s not a bug, then it’s a pretty pointless action.
I have a video of it actually, I’ll post it when I get home from work.