I can see where you're coming from for sure. There is nothing stopping lemmy.world from defederating as well which would clear up any confusion like this at the cost of further restricting its users. It would be nice though to have something like a visual warning or something letting the user know if they are visiting a community that is hosted on an instance which has defederated from their home instance. It could be something as simple as a little icon that if you click on it will link to a page explaining what defederation is or something.