It could be possible that the transformations were to heavy on the servers, and, if brought on to Live, would have caused a lot of lag.
Also, it could be possible that potions may undergo a level cap increase. Possibly they are just saving these for when they raise the cap on Potions to 25/30, if they do, so that they don't have to come up with that many more extensive ideas for potions.
Either way, don't get your hopes down just yet. If they had the gusto to actually make them and put them out for a brief moment, I'm confident Disney won't let them go to waste, and put them in sometime in the future.