Nah. Not in Thedas, actually. The Necromancers deal with spirits, not souls. The one Necromancer in your party is an extreme outlier in being able to talk to the dead, well more let them talk to the living. It seems to be one way. He's the only one who can do it and it's probably a plot point why he can. Spirits and demons aren't the result of people dying (directly). Necromancers call spirits to posses dead bodies and keep bodies in good shape. Basically Ethical Abominations where no person's will is subverted and the spirit can be easily forced out from.