Some of 2000s Japanese imageboards worked a bit like that. Replying to a thread bumps it to top of a board, last thread in list of threads is deleted when total reply count exceeds a limit, bumps stop working for older threads. Thread MHT archives can be captured and uploaded to fileshares if needed. Remaining time is controllable by internal parameters, but also self regulating by traffic because of bump system, to somewhere between just few hours to over a week. Discussion worth continuing can be done so by starting a new thread.
Many from such communities later migrated to Twitter, despite the board still operating. Wrestling virtue signaling game while earning buzz is easier for those with that background, and I still come across accounts on timeline with clear influence from there.
Massive upgrade from there to Twitter was forced individual consistency with account requirement - absolute anonymity leads to people without working theory of mind going gung-ho with total release from normally enforced multi-agent world modeling, and that's just malicious, like rejecting concept of criticism, possession, even nominatives.