Another way I like to think about this feature is as Consent Widgets, where instead of trying to trigger people on their timelines and getting rewarded for that, you erect some friction akin to a subject line, creating a layer of inferred consent in the timeline experience. A Consent Widget asks, would you consent to opening up my post about an intense topic?
This is at the heart of a lot of the current friction: How do we grok the concept of Content Warnings / Content Notes, and as a result, how will they be used? Should the onus always be on the poster, or often also on the recipient? What kind of personalised filters can and should we build, and who is responsible for maintaining them?