I don't follow streaming or use twitch so I can't speak to any context or consistency in this approach.

However, I think there is a generally-accepted concept in journalism that sharing of certain kinds of potentially inflammatory information ought to be done with caution. This is established for quite a while regarding reporting on suicide, which is thought to increase the likelihood of other people following suit in the near future.

When it comes to "manifestos" of people who have conducted showy shootings, you have to remember that these are for the most part racist, anti-lgbt, anti-muslim, misogynist, anti-immigrant motivations. There is a feeling that it isn't a good idea to widely share hate literature involved in massacres, because people could (and have) taken them as inspiration for further fashy violence. If you are just broadcasting white supremacist "ideas" out into the media, it's impossible to inoculate all the audience, and you will inevitably end up spreading and promoting race hatred.

So if you imagine yourself as a liberal who can't tell the difference between different situations, who just looks at things in the most infantile simple way, and one shooting is the same as another, this probably makes sense as a guideline.

Naturally, this rule only applies to individual shooters who are not directly affiliated with the state. Other kinds of violence are somehow exempt.

Journalism has been in a death spiral for some time now whereas gaming it a money maker. Twitch is a gaming website. Why would they want to have anything to do with journalism? Hasan is trying to use their resources towards his own end. But there is nothing in it for twitch. It will only cause them to become entangled in all kinds of grief.

They will exist in tension with each other, trying to go as long as they can, until they cannot.