"it does suggest that avoiding your triggers [...] provides no benefit"
This is the part I'm sceptical of. When I look this up, I mostly find articles like https://theconversation.com/proceed-with-caution-the-trouble... (and the underlying studies), which mainly address the question of whether reading a trigger warning and then consuming the potentially triggering content is better than just consuming the potentially triggering content without a warning.
(The article also mentions a finding that trigger warnings have "no meaningful effect on an individual's [...] avoidance of this content"; but I think that's entirely compatible with a world where most people consume the content regardless of the warning, some are more drawn to it because of the warning, and some (including the few who are truly vulnerable) avoid it because of the warning. The effect on those vulnerable few is what's most relevant here. The article does briefly mention "unhealthy avoidance behaviours", but in the context of one university's opinion and without supporting evidence.)
What's the best evidence against trigger warnings as a means of enabling traumatised people to make an informed decision on when (and whether) to confront their triggers?