I recently had a random chunk generate on a game crash. I was throwing eggs into my chicken farm and Minecraft crashed on me, when I rebooted the game my chicken farm had a chunk randomly appear in the side of it. The chunk also removed a portion of the villager farm I had been building.

Besides having a new chunk appear in the area, it moved the section of the villager farm (that the chunk replaced) to a new area. The doors and the entrance into the farm were all still intact, just moved about 100 blocks away. It also moved a random chunk of roofed forest into the plains beside it.

I just thought that this was a interesting glitch y'all should know about.