I'd be very disappointed to have a ''time-slip'' and to find out that, in the new timeline, the world was exactly the same as before except for
the fact that an aging evangelical pastor was still alive.
Even a difference as small as this would have thrown up an ever-increasing, alternative causal chain of events to those in the new ''timeline'';
a farmer sneezes in China, a butterfly flaps its wings in South America... etc. etc.
This is just a case of people's memories being inaccurate when recollecting information that does not have great personal importance to them. The
fact that Billy Graham has been in ill-health over many years, he's retired from his preaching and that his wife died a few years ago, contribute
towards the false, distorted memory of his death being implanted in people's minds.
Add to this the psychological phenomenon - which I can't accurately recall at the moment ( a problem with my memory
) - where someone starts
believing in something untrue and forming imaginary memories of the event happening because of other people suggesting and describing the untrue event
to them - and I think that that is pretty much all there is to this.
It's similar to Fidel Castro; a lot of people think he's dead because it was widely reported that he was ''close to death'' about five years ago
after suffering from illness. Because he's not in the public eye much anymore, some people, when thinking about him, have their 5-year-old memory of
him being near death erroneously recalling that he did actually die.