Conversations should definitely be encouraged equally even if they're not "hot" and seeing new posts at an hourly frequency. Some people have high signal precisely because they're doing things other than authoring high-quality prose for a bulletin board, and if their participation is only incentivised when they spend hours catering to artificial engagement metrics, then they might avoid the place entirely and stick to doing their thing and posting about it through services that deliver content sequentiallly rather than algorithmically.

I like to open a good post and see a lot of comments there pounding about the topic and learn within it. In the same way is sad see a comment zone empty for a good content for any reasons.