The issue is.
The social aspect didnt exist anymore before rdf then it did after, the sheer concept a system widened the amount of players you could meet and talk to, introduced battlenet accounts which allowed you to talk to your friends in other blizzard games and when playing the opposit faction is ludiciruous.
RDF expanded the quantity of people you could meet. Group, and talk to massively. The problem is:
People in game pre guides and everything that became more and more.popular were forced to talk for base information of the game, when ur new to the game ur generally more social then you are when u become a regular player.
Because u lack a click, or friends in the game prior and as u go on u find ur guild, u find players and create ur click and ignore those outside of that naturally.
Players want to cling to their very first experience of the game and want that back, and you simply cant.
What no rdf allows is simple: social consequence still exists, everyone u play with is from your server, so top server guilds arent invalidated by other servers guilds, server firsts are still the goal and ninja looters and bad players are generally easier to become common knowledge.
People chase a reason to why theyre not social instead of accepting the fact they arent interested in random players, if your the type of player to chat in Pug groups RDF wouldnt stop you doing that.
And its Massively proven in retail.
M+ and mythic dungeons arent on RDF theyre premade groups and the behaviour used in those are identical to RDF modes of the game.
Ion isnt bringing in RDF becahse the players they want to captivate with classic are those that left becauee of what retail is today, to retain both sides of the playerbase.
RDF never killed the social aspect.
Easily accessed game information
Teamspeak / discord platforms.
Guilds.
And common knowledge of meta.
Killed the social aspects of the game and they have come to classic with those games and shown with or without RDF it has died.