To be fair, it's not really known if Sasuke did break out of it or if Itachi let him out of it, obviously Itachi never intended for Sasuke to lose so it wouldn't make sense to keep him in Tsukuyomi which is an automatic loss otherwise, and we know Itachi can do this because he did it during their fight with Kabuto.
And Kakashi seems pretty convinved that Genjutsu resisting methods are irrelevant to Tsukuyomi, and he's as good a source as any given that he fell victim to it.