I have two old villages previous to 1.14, I modernized them to have workstations, beds, and a town center, and I spawned and iron golem using blocks in one of them.

Iron golems can now naturally spawn when there are enough villagers reunited in the town center (where the bell is). When the golems spawn, in both villages, they always spawn inside houses, causing them to suffocate in the ceiling and walls and die.

This also happens on the new houses I've built