Rework How Suicidal/Self Harm related questions are handled
If someone talking about suicide and/or self harm in chat, then banning someone from a platform that could potentially provide vital contact or support to them is not the answer needed for helping them.
This reddit post made by reportedly a health professional describes their experience with the issue
While messages glorifying the acts should not be promoted or allowed on the site, it's important to not get rid of a potentially vital way of contacting someone who could be in serious danger. Instead, provide them with hotlines, or other direct ways to get them the support they need. The same could also apply to channels posting content like this via video. There could be better ways to deal with this, however, I am not a mental health professional, so what that could be is not my place to say, however, I implore those at Twitch to reach out to those who may know so they can handle this in the best way they can.
The reddit post I linked explains some of the reasoning behind this suggestion.