This cannot be true. Science marches ever forward. We are learning new things constantly and no knowledge has been lost. New findings from new studies always augment our growing base of empirical facts and evidence. We are more advanced today than anyone, anywhere in the past.
Knowledge gets lost constantly, there is just so much of it that it happens on the sidelines. Just think about all the old software and hardware stacks which have been replaced and the people who were experts in it are now retired and dead.
Even the knowledge of today is not well-preserved. If Stack Overflow were to disappear tomorrow, how many other resources would there be for all the programming knowledge? There aren't that many great programming books. Thank god Github has been archived in the Arctic Code Vault. It could all be lost in a few decades.
Even cultural significant things like how to produce Saturn's F-1 Rocket Engine gets lost. The manufacturing processes, machining techniques, and supplier expertise is gone and wasn't written down. That was just ~60 years ago. The recipe for Fogbank, a material for nuclear warheads, was lost, and it took 5 years to reverse engineer it.
It is not clear to me how this refutes the article. Can you explain a bit more? Do you have an example of a piece of data that lasts forever by virtue of these facts?