I believe that the defederation is only one way (from .cafe's side), so while your instance will no longer request new content from .cafe, if a user from your instance manually inputs a direct link to a post from .cafe, I think it can still be fetched one at a time (might be somewhat wrong about that, but I'm pretty sure that's the gist of it).

However, any posts or comments left to that community would only be seen by other users on your own instance, it would not federate out.