Removing the Gnome Enlargement Balm was one of the negative changes that turtle implemented, as it was in-game for quite some time. My guess is that it seemed to be part of their move to try to "clean up" some of the more-goofy/buggy things available in light of their cleaner look towards the end, and their shift towards their GMs being both more numerous and less active in public.
With the recent patch, the vendor that had this had it removed from his inventory, probably due to just parity updating with the "real" 1.18. But I think people have a lot of fun with items like this and the horde equivalent (that makes tauren shrink down) so these items being readded to the respective vendors would be a good change.