It DOES work you are mis-understading what the promise was. The idea as that for MOST of the hair Grooms upon launch, there would be high end Strand Groom and accompanying Cards that can be used alternatively. (The button you speak of (Checkbox) But this is not to turn the grom INTO a Cards it is to make use of the isting Cards avaiable (or not ) for the given Groom. There caveat being that for some of the hair Grooms, there are only 0 and 1 LODs (and though it does not say so, the same is true for Cards for those particular grooms.).
So for most of the Grooms the Cards work, but theGrooms with no Cards (and LODs only for 0 and 1) are the ones that generate the YELLOW Text Warning in Bridge.