Like many have pointed out, it really is different from wavedashing in that it's not as useful. Not only is it not usable mid-air or while landing, but, it doesn't allow the use of a jab facing the same direction as you're moving. As stated above, it probably won't be used as consistently as wavedashing either, which was a fairly simple input in comparison. All I can really see this being used for is subtle spacing manoeuvres, which might make for some neat, though very situational advantages. But, again, not really that big of a deal, in my opinion. Similar pivot techniques have been around for quite a while, no?
I have a sneaking suspicion that those who discovered that the AT was still present in Smash 4 kept quiet of it until now, due to the fear of having it ''fixed'' in a patch. However, with Sakurai saying there are no plans for further balancing patches outside ''glaring issues'', the chance of this getting patched out seems rather small.