That button is in fact missing in the 0.27 client
There is code in the game to actually keep track of whether the button should appear in the wardrobe, but there's no code for actually displaying/handling the button in the wardrobe. I'm aware of the issue, but didn't bother trying to fix, it didn't inconvenience me enough
At this point I'm also just waiting impatiently for 0.28. It should be out soon enough and putting any more time into fixing 0.27 doesn't seem worthwhile. It's only Kate's playthrough that's really borked, and you can play that properly in 0.25 anyway. 0.27 is a Max update and doesn't add anything significant to Kate's path besides better questlog descriptions.