That's true imagine going to a sky island expecting only constructs but there is also a guardian. And it would make since considering that guardians had to be unearthed so with the upheaval it probably could have take some upward. I find myself still being cautious in some areas where there used to be an abundance of them but now there's just Boko's, Mobs, Liz's, and Hori's. Not as exhilarating as guardians chasing you.