Edit: yes 1 to many communications existed but they either required expensive publishing or they were tied to a physical location (eg a physical notice board). Internet forums are globally available for anyone who is interested to read or publish and that turns out to be phenomenally powerful but in a way that pre-internet people could not have conceived of
"As soon as the Paris contract released the telelectroscope, it was delivered to public use, and was soon connected with the telephonic systems of the whole world. The improved 'limitless-distance' telephone was presently introduced, and the daily doings of the globe made visible to everybody, and audibly discussible, too, by witnesses separated by any number of leagues." - From the London Times of 1904, Mark Twain
“So, unless aware of this dynamic, we shall at once move into a phase of panic terrors, exactly befitting a small world of tribal drums, total interdependence, and superimposed co-existence.… Terror is the normal state of any oral society, for in it everything affects everything all the time.…”
Roll back one academic generation further to McLuhan's mentor, Harold Innis.
It was Innis who'd first drawn the connection between medium and tenor / characteristics of communication. See especially Empire and Communications and The Bias of Communication.
The WELL was available in 1985. One of the motivations for designing the original Apple I was connecting to mainframe based bulletin boards, in the 70s. CompuServe started selling dial up access to their service in 79. GEnie was available in 85. Delphi was available in 1981. Quantum Link was available in 85 and became AOL in 88.
Maybe not back then, but I got distinctive usenet vibes back when I read Ender's Game (novel, 1985); nowadays I'd probably get reddit or facebook vibes. Not sure what parts of message boards concept existed in the 1977 version.
Edit: yes 1 to many communications existed but they either required expensive publishing or they were tied to a physical location (eg a physical notice board). Internet forums are globally available for anyone who is interested to read or publish and that turns out to be phenomenally powerful but in a way that pre-internet people could not have conceived of