I might be a bit late to the party. I just found out about the GSoC program yesterday and submitted a brief proposal ! 
I just posted a potential enhancement or plugin that could be built into the composer / editor window. Link the discussion is here.
The gist of the plugin/enhancement is that a user’s post could be pre-flagged and they could be notified that what they are about to post may be toxic and that they should take time to review it. I think the Google Jigsaw team has been working towards developing something like this. @codinghorror linked google’s perspectiveAPI. I haven’t had time to play around with it myself but it looks promising from my initial glance. Maybe a plugin that uses that api?
What are your thoughts/feelings on something like this?