As post volume increases, is there a plan for topic hierarchy or subscriptions?

Already, new posts are getting knocked down pretty quickly on the "Recent" tab. This pace will only increase. Incentivizing first votes is awesome, but more changes will be needed to triage everything. Let's say there's a topic called Jokes. I want to start Knock-Knock Jokes. Will we eventually be able to create a new sub within a topic? Are topic subscriptions part of the plan too? Thank you.