Simply put,non-village structures spawn in them. Also, the strcture spawn frequency seems to have increased, but maybe that's just me.
Screen (notice the gaping hole in the structure)

#179 happens in the latest 1.11.2 release as well. Seems to occur most often on a server. I had very few occurrences of this while testing single player worlds. Doesn't seem to matter the world types I've tested (vanilla, quark_realistic, biomesop, ATG) nor weather the world chunks are generated by a player or the server (like SpongeForge + Nucleus).

Also does not "appear" to be specific to a RC village structure type and seems to happen randomly with all of the available types. Perhaps this is caused by the Cascading WorldGen?

Screenshot seems to be missing.

Edited

I believe that was on my ToDo list at some point. It doesn't happen too often though so it doesn't have a high priority.