Basically what the title says. I summoned a NoAI villager and teleported it to a certain rotation. Then I left the chunks. When I came back, it was at the 0,0 rotation.

It seems that this will always happen, because if i summon a villager and give it a preset rotation without the NoAI rotation, then give it the NoAI tag, this bug will still occur. I am unsure if this works with other mobs.