So, in light of a discussion that happened some moments ago in the OOCC with Kretnub, I've been asked to post my question to you nubs on the forum.
How possible is Warlock to Necromancer? I believe I can validate it rather well, but opinions on the validity of it would be nice.
Necromancy was introduced by the Burning Legion*, the Scourge was a tool to prepare Azeroth for its destruction by said Legion.
I think it's quite possible. But...!
Individual necromancers might have a distaste for fel, and individual warlocks might have a distaste for necromancy. Strictly speaking, the Legion and its followers are not on good terms with the Scourge and visa versa, so a warlock might have trouble finding a willing trainer.
Also, the transition might be easier for warlocks who were originally frost mages, or warlocks that use more shadow.
*The Faceless Ones have their own brand. But, who knows anything about them.