It's happened several times that when I start on a new house and I look at what the new items are for the villager, the Stone wall is in that list. For instance, now I'm doing Sprinkle, who has the full Ice series, including the wall and floor. But there's also the Stone Wall as a new item! This wall is obviously not related to the Ice series at all. I've had this happen a lot. Not on all the houses, but say on one third of them (I haven't kept count).
Does anyone else have this as well? Or am I the only one?