This is true to a degree (reminds me of the old MAD Magazine adage that "MAD was at its best whenever you first started reading it"), though I feel communities

This is true to a degree (reminds me of the old MAD Magazine adage that "MAD was at its best whenever you first started reading it"), though I feel communities usually have a localised version of Eternal September as well. At least if they get popular. Eternal September on Usenet would hence be different from Eternal September on Reddit, Facebook or Hacker News.