There is a lot of stuff people hear and then keep repeating, but that has no actual basis other than it sounds plausible. I’m aware of one rigorous paper that, while not really focused on kitchen uses, found that the posited risks of lead from the nozzle and bacteria being trapped in the layers didn’t hold up. The author has a blog where they expand on it ad tedium.
For a candy dish, I don’t think it would be a problem at all. If you were using a 3D-printed bowl to eat porridge out of and not washing it… well, you might have other issues.