May be related to MC-107422, but I wasn't sure.
It seems as though Woodland Mansions can generate at a much higher y-axis value than the surrounding area. I found an example of one jutting out of a roofed forest.
The example in the picture is located in:
Seed: 3.14
X: -2024
Z: -632
Cannot reproduce. Please verify you provided the correct seed and/or coordinates. When I teleport to the location, I only see extreme hills.