Before social media how long would it have taken to find out this loose of a connection had passed away? My guess is months to years if ever.
Families would call all the close contacts and relatives to make sure that they knew.
For several years after my father died in 1985 people called our house to speak to him. Most were not close acquaintances but some were still pretty shocked to hear of his death.
I think people generally still do this? When my mother died a few years ago we took turns calling her relatives and close friends. We wanted them to hear the news verbally.
Such a Hacker Newish assumption. In the so-called real world, most people travel for all sorts of other reasons than conferences.
It was never received.
And therein lies the difference.
Still much better than the obituary world of yesteryear. You could then also say the info was transmitted but the rate of receival probably low.