I personally wouldn't view animating the dead as an act to be inherently evil, but according to you, you've already outlined necromancy as a whole evil. He's still puppeteering a corpse, even if he just 'poofs' it from nowhere. The moral standards of the country they're in also makes it seem like an Evil act.
I'd tell your player he should save his necromancer for a more fitting campaign.
Ah, my bad. I'm actually for this ability not being any where as evil as normal animate dead. It's basically a summon skeleton spell and not a "let's defile bodies" to make undead spell.
I misread Necromantic Servant in my first pass, where I thought it requires a body to "turn" into a skeleton or zombie. It doesn't seem to need a corpse to work.