I've noticed that almost all WICG threads end without conclusion, as is typical of mailing list threads, but in many cases the suggestion or proposal is taken forward into a repo or other forum. Would it be useful to post a final message to inactive threads and then lock them to further comments?
For example, https://discourse.wicg.io/t/content-performance-policy/1380/ describes Content performance policy, and ends without resolution, but CPP is now superceded by the Feature Policy API, I believe, so it would be valuable to future searchers for such threads to have a resolution.
Sometimes such a message is posted, eg. https://discourse.wicg.io/t/proposal-for-a-web-background-sync-api/1118/4 - but to avoid that message disappearing as the thread continues, the thread could be locked at that point.