This page is a work-in-progress.
First a few recent observations…
There was a recent video released by Josh Strife Hayes (JSH) reviewing 100 hours of Everquest. He talks in the Everquest video a little about how MMOs evolved from MUDs and were primarily chat systems with gaming as a secondary function. Even in games like World of Warcraft, it's almost as if raiding and other events are just vehicles through which to get gamers to interact with each other. In his video on the epic in the MMO genre, JSH briefly mentions matchmaking and other improvements that were made over the years that detracted from the social aspects, making the games less MMO and more single player RPGs with other people.
Recently there was also a video by Force Gaming asking WTF Happened to MMOs. While it was light on content, it does a good job of pointing out something most MMO fans don't know, that there are a record number of MMOs in development now compared to any point in history.
Lastly, there has been a recent long form video on the history of EVE Online by Fredrik Knudsen. This video goes in depth into the history of EVE both as the game studio making it and the players playing it as well as the corporations/guilds that formed up over the course of the game and their history and social interactions.