Trees can generate with dirt or dirt path instead of leaves

Confirmed. I've already seen this a few times.

Cannot reproduce.

I have seen this multiple times

happens in villages where a path intersects with a tree

Still relevant in 1.18

On Java snapshot 22w44a the trees in question can be seen with

seed: -8238285669479744154

coordinates: -698 74 3518.

Note: I wasn't able to recreate the bug by recreating the world.  I had played in that world for a several game days before I arrived at that location.

would it be reproducible with the /structure and /setbiome command? if you were to spawn in a village then set the biome to oak forest would that work?

In 1.20.3

Affects 1.20.6 and 24w19b

Can confirm for 1.21.3