Man I remember watching this happen in realtime to r/AbruptChaos. There were two simple rules 1.the video must start out calm 2. there must be an abrupt moment where multiple things start happening at once. It slowly went from every post being great, to more than 90% of them being chaos the entire video or only having one bizarre event. Idk if it was moderation getting loose or karma-farming or both but hopefully its a while before that starts happening here.