Does Epic Typhon stops dropping legendaries past a certain level?
Solution 1:
It's been a while since I played Titan Quest, and I can't remember how far I got into redoing the later difficulty levels, but if the bosses follow the same rules as the normal monsters in the game, if a monster isn't dropping items it's not because you're too high of a level, it's because that monster isn't strong enough to have a % chance to drop what you're looking for.
ie- a max level character will have the same drop chances from normal level bosses as a character of appropriate level.