Yes, it is working as intended. The idea is that each instance is responsible for pushing content once, then it's the responsibility of the receiving instance to process and display the content to the relevant users/accounts.
As a side note, if everything was "re-pushed" out, the load becomes even more on the "source of truth" for larger communities with wide federation and a lot of new content generated locally and remotely. I could see this being leveraged to take down servers by simply spamming really large communities (with large federation) with small content forcing the "source of truth" to now "re-push" the content to every server that is knows about for every single new comment, or reply, or post.