AFAIK you can force this through whatever graphics software you use? I've never noticed the effects of bilinear filtering, or a lack of filtering for that matter & it would stick out like a sore thumb if it was a the case & a lot of people would be bickering about it.

Despite your multiple wikipedia links, I don't think you fully understand what texture filtering is & how it applies to a game like Valheim.

If something like this bothers you, I would avoid the game as you'll be fighting from the ground up to turn it into something that it's not.