I have been the first user on my instance to subscribe to a few “remote” communities. It seems like basically nothing those remote communities from before I subscribed is can be viewed on my local instance. However, after subscribing to a community, anything new that happens there including posts and comments from users on third instances will appear.
In cases where someone else from my instance subscribed to a remote community previously, the full content from those communities from the time they subscribed is also available to me.
I may be misunderstanding your question because I never used Mastodon.
Dave2D published a video praising this: https://www.youtube.com/watch?v=bIPl71ZeOYk
There’s not a lot of activity here yet. I think that a single post for each whole race weekend would be plenty for now. Hopefully, at some point this place will be so crowded that we need more discussion posts. I’m looking forward to that day. 😄
It was discussed in this post.
I think the conclusion was shared in this other post with the following quote: