I think VD Spellslinger was popular for being popular. I tried the build myself and those components of the build did not feel like they needed a nerf. Most Spellslinger builds do not scale quite as well into the end game due to mana reservation and occupying a support slot, while being quite good(maybe too much) in the early game. If they do touch Spellslinger, they'll have to compensate its endgame, otherwise it's a dead archetype.
The combination of glancing blows, necro, bone offering, and recovery on block will likely get some adjustment. My guess the recovery on block will be halved by glancing blows, thus making harder for necros to reach block cap.