Unnatural underwater ruin generation.

I loaded up a new world in the latest snapshot "19w41a" and I was looking for the new bee nest and I came across a structure. I thought it was a dungeon because I saw zombie looking guys. I was wrong, when the chunks started loading in I realized that it was a underwater ruin. I'm pretty sure there not supposed to generate on land. Kinda strange, because the water zombies were there too.