They won't promote it because there's no way they can pull these rap verses off live. And even though they use backtracks, they try not to go full lipsynch on stage.
Plus, the nature of the lyrics must make them uncertain, especially Cube. I bet the company was not super comfortable with Wife as a pre-release.
I think they can definitely pull it off live. The real issue would be the feminist meaning behind the song and the vulgarity of the lyrics in korean