I really have no desire to fight, but I think the whole "triggered" argument is mostly a strawman. Mostly, because sure, it does actually happen that some one has some sort of PTSD and can in fact be triggered in the clinical sense, but that mostly that word is appropriated to describe a wide range of much milder emotions with varying levels of discomfort and which even when great don't involve something that involves a clinical or medical condition. As such, use of the term is a sort of appropriation that ultimately detracts from the understanding of the real suffering of a very small percentage of people, while at the same time serving as a way to claim moral high ground on the issue in a lovely, "Shut up! How dare you!" sort of way.
And, as evidence of that, I'd like to point out that so far as I can tell no real triggering was involved in this controversy and it's dominance of the conversation while complete ignoring what actually happened here is well par for the course. And heck, "triggered" has become such a part of the vernacular now that it is used to refer to all sorts of things.
The players at the table found the whole situation awkward, distasteful, and unpleasant to the extent that GM lost, rightly I think, all the trust he had from his players. What he did was in a word, "creepy". That in itself is sufficient grounds to suggest it was wrong. There are lots of other ways in which I find it wrong, that I won't go into here. But what I didn't notice going on was anyone being "triggered".
If feel "triggered" has become the sort of thing that shows up for the same reason Godwin's Law has such predictive power. If it's the only thing in your toolbox for describing harm, then that's what you reach for. It doesn't actually reflect what is really going on 99.99% of the time. And for all those cases where harm happened but it wasn't a "triggering" event, it rather misses the point.
Deliberately sometimes.