I don't have any psychiatric education, but from what I've read written by actual psychiatrists, avoiding any mentions of traumatic experience or anything that could remind of it, forever - is not considered the best way to handle the problem. Of course, there could be people that are so severely affected that any mention of the subject is intolerable to them - but I feel like for most people "trigger warnings" rather function as establishing the norm - that some things should "trigger" them and if they don't maybe there's something wrong with them. If this is the case, I can see how it could be counter-productive.