The way I see it community is just that, a community. It is not a place where people gather, but instead it is a collection of people. You are not limited to meeting your friends in a particular place, you can meet them in a variety of different places, but still be a part of the community. There may be multiple /c/askhistorians, so sub them all and you will be a part of the community in them all. I hope that makes sense.
A recent job change caused me to revert back to my old G-Shock watch instead of my Apple Watch. I was setting the time and date and noted that the date “only” goes up to the year 2039. Even though it is already over 20 years old, I fully expect this watch to work well past 2039; I have no expectation that the Apple Watch will. Even if it technically functioned, the software and protocols would have been long abandoned.