Yes, the article seems to worry about ‘what would happen if TODAY there was an event…’
If an event happened today there would probably be an immediate problem, but knowledge of various civilizations would still be intact with those who survive.
If an event happened today and there were no survivors, then the question is moot.
If an event happened today and there were a few survivors who have offspring that repopulate in the future, then some scraps of what was would continue along as mythical tales.
IF an event happened today and thousands to millions of years later some sentient beings from other portions of the universe discovered our dead planet, there is then, since they had the ability to get here in the first place, a possibility that broadcasts we’ve inadvertently sent out via television and radio signals all those millions of years ago would be received as echos bouncing around that might be readable or viewable or listened to. Of course it’s also possible that by then the echoes may also be degraded, but also possible they are not.
One of the ways to try to preserve civilization would be to send information out into space and made available in all formats from actual books, to film, disks, records in both spoken and written word, in bionary code, sound etc. There is always a chance that one or two out of many would survive and eventually orbit back to homebase on timed schedules, or be sent in a straight line off to be found by others.
No matter what human beings do though, everything is temporary. If all was lost to the children of our great-grand children, I have great faith that they, as intelligent human beings, will, without our assistance or even any knowledge of their own history, recreate a thriving civilization who will in turn, repeat and repeat the same paths and even mistakes we travel today.