I think this drop is still bugged currently.
I've tried to get one to drop from the boars in Balenos Forest (near the new Dastard Bheg spawn location) since they mentioned being able to craft the Artisan/Master version of this head in the Feb 23rd 2022 patch notes, but no luck.
I was able to get both the Stuffed Bear Head and Bear Hide Carpet from the Balenos Bears in the same area though.
I understand you're contacting us in regards to the item Stuffed Boar Head. I'll do my best to clarify the situation.
Please note that how to obtain this item is hidden information that is intended to be explored and uncovered by the player base and not something that our team is at liberty to reveal. Consider it like the Fog of War in a typical strategy game, which hides elements of the world until a player explores and reports the findings to their team.