I do find it incredibly suspect that they don't fight on-screen, but they are implied to fight, would be the possible rationale that they make it in as full DLC characters with movesets and everything. But as for Korean sword users in story modes, they've been using Xianghua and Mitsurugi styles, for female and male characters, respectively, so they could have had Hwang using Mitsurugi's style, but didn't, so... maybe. I'm just not convinced yet. You could say the same thing of Edge Master, as he is implied to fight several times but doesn't, but imagine the negative response if he's in the season pass.