First of all, @JazliAziz thank you for taking the time to give us this great feedback! I'll address each point with some details:
This kind of scenario could benefit from a "bump" back to the top of people's home feeds, but at the same time I know it wouldn't be feasible to bump every single conversation that receives a new post. Maybe someone else could come up with a more elegant solution?
We've been looking for a solution to this problem for more than a year now. On one hand we want to show people fresh new content, but at the same time also ongoing conversations.
By default we chose to go with the "Interesting" sort order in the feed, which is a combination of what is most relevant to you, level of engagement in a conversation and how recent it is. We assumed that if you are interested in an ongoing conversation you'll either follow it, or by posting in it, you'll be automatically notified.
Another options we considered by default is "Active". This works exactly like old school post bump. Whenever there is a new post in a conversation that you haven't seen, it will jump to the top of the feed.
Both Interesting and Active options are in the dropdown in the feed and you can manually choose your preferred sort for most feeds For You, Following and All. They are all independent feeds and will stay sorted that way until you change them.
Would love to hear if anyone out there has a better solution for this problem!