That entirely depends on who your subscribed to. Personally all my stuff channels like Numberphile/computerphile, or SmarterEveryDay, and plenty of Blender3d tutorial channels, animators, and a whole bunch of other informative channels.
As how Marx outlined Communism as the evolution of Capitalism once it reaches a scale of production that everyone can have their needs met, resulting in a classless, stateless, moneyless society, then yes authoritarian communist is an oxymoron.
From what it looks like to me in testing, in any given instance All is any other instance that communicates with said instance, Local is all communities within an instance, and Subscribed is just the communities within the instance you have explicitly subscribed to.
Yeah it does break the pattern but there isn’t much of an option that keeps everything super clean like tjat, unless it’s something like ctrl alt N for a private window.