Good search can solve a lot of things, but I believe that structured auto-archiving is needed as well. Some scenarios:
- A user may want to see how many posts did he have on his user talk page each month.
- A user may want to check what things were discussed around the time of certain news events, holidays, MediaWiki software changes, etc.
- A user may want to find a conversation that is hard to find by words, because the relevant words are too common and yield too many results, but he does remember the time when the conversation happened.
- It may sound like circular logic, but own internal engine's search indexing is far from perfect even for English, and for most other languages its morphological support is even worse. An archive by dates would be a reasonable fallback for such languages.
It makes sense to me to see automated archives of Flow conversations by month. I imagine something like a box that shows years and months, and clicking a month would show a page with all the conversations from that month.
I don't have statistics about the number of conversations by month, but I imagine that even in the busiest talk pages a whole month could fit reasonably on one page. Maybe some especially busy ones could be split by weeks. I'd love to see statistics, if anybody has them.