Absolutely they should, and when I worked there that was known as "protecting voice", that content has always been explicitly allowed because it is free expression, even if reading it can be difficult for some people. The same with someone posting images of healed scars because they've been overcoming their self harm.

The content I'm talking about is graphic photos of suicide and self injury, fresh, blood soaked cuts, bodies hanging, graphic depictions of eating disorder (that goes beyond "thinspo", which is more borderline, and so downranked and not recommended rather than removed).

It's the latter that we believed (based on the advice of experts who we relied on for guidance) is harmful when consumed in large quantities.