The only problem that came of this removal patch, was that blacksmiths at the time only remembered or kept the recipes for the specialty they had known at the time.
A pre-patch armorsmith knew the Outland armorsmith recipes and still knew them after the patch. However, that same armorsmith was and is unable to learn any of the other pre-patch Outland specialty recipes because Blizz removed them from the trainers completely. Same goes for all the other blacksmith specialties.
I've yet to hear a reasoning or explanation why this is.
Edited, Jul 1st 2012 3:33pm by Azaza
"...for he suffers the worst fate he can know, and that is to know that he dies."