The bug
One door is open in taiga_shepherds_house_1, which traps villagers.
How to reproduce
Run:
/setblock ~ ~ ~ structure_block{mode:"LOAD", name:"village/taiga/houses/taiga_shepherds_house_1"}Look at the debug screen and the left door should be open
This makes the loom inaccessible. (for villagers)
Confirmed in 1.16 Pre-release 8.