I always +1 for more hairstyles. Personally, I'd like to see a better selection of shorter styles for women too. Tbh I feel like a lot of problems of finding a suitable style could be minimized if they just made all the styles available for every race/gender.
Also, talking in very broad strokes about medieval Europe from a historical standpoint, knights (the nobility class) preferred to keep their hair long as a status symbol. Peasantry kept their hair short or shaved because it was easier to maintain or, in some regions, due to sumptuary laws. Having their hair cut was often a punishment/act of humiliation for knights/nobility and represented a loss of honor or stripping of their rank. Feudal Japan also felt similarly about their hair but I think everyone kept most of it long and tied into a topknot with the front shaved.
It's really a more modern sensibility to prefer short hair for warriors. I don't know the exact history of it but I imagine it has something to do with lice infestations during the trench warfare of WWI, which was real nasty business.
So, in the D&D fantasy setting I'd say it's safe for your happy zweihander wielding, heavy armor wearing warriors to have long lucious curls/dreads/what have you.
