Caves and village structures can generate inside icebergs

I recently found a village near a frozen ocean biome and found a house that almost connects to an iceberg, so I decided to transform it making the inside of the iceberg part of the house. However, inside I found (very cool) caves and village structures such as a farm inside the iceberg.  I don't know if this is a bug or a feature or invalid but I honestly don't care if you fix the caves part, since it is really cool.  

 

how to reproduce: 
seed: 2485810850066297597 on 1.18 pre-5 

cords: /tp -1526 65 2293