I just started trying out Warlock for the first time on the test server. I noticed when the imp kills something without me personally tagging the mob I don't get exp. As someone who has played Hunter I am used to solo pet kills giving exp. My question is did Warlock pets soloing things ever give exp to the owner of the pet? It's possible it's just my private server that is wrong.
This was how it functioned in vanilla for both hunters and warlocks. You need to deal some damage to the mob in order to gain experience
This. So yes you have to participate in the kill too. Works as it was back in the day.