According to every Wiki I've looked at to plan out my character, all spell casters gain a new cantrip at level 4. My party just hit level 4, but my character, an Archfey Warlock, didn't get to pick a new cantrip at level 4. It seems to be just my character. I went back to camp and leveled up Wyll and he gets a new cantrip. Shadowheart and Gale both got cantrips as well.
