Everything has its "shadow" side. I think word trigger is appropriate as information that sets of memories/emotions of trauma or something. The shadow side is thinking of trigger as annoyance, as you said. It devaluates its original meaning.
You can take any word or information and use it in the context of conversation also. Someone may think I am antichristian because of some of my posts today, but I was just stating one aspect of it, not generalizing.
Language is a very strange phenomenon.