The Vinland Map is awash in 20th-century ink
news.yale.edu
news.yale.edu
Ferrajoli sold the book and map for $3,500 to a US dealer, Laurence Witten, who also further obscured its origins[0]. Later, a benefactor purchased it on behalf of Yale, for $300,000
Notably, when Yale announced their discovery of the map, in 1965. The original source, Ferrajoli, was already in prison in Spain, charged with stealing other manuscripts (which he had also sold to Yale the year before)[1]
edit: added a citation
[0] https://www.maphistory.info/saenger.html para. 13-
[1] https://www.nytimes.com/1964/11/07/archives/dealer-defends-r...
This doesn't change any understanding of history.
Archeological evidence found in the 1960s proves quite clearly that Norsemen reached the Americas 500 years before Columbus. In fact this evidence turned up - and got quite a lot of attention - in the 1960s, which is when this map was first published. But by the 1970s, analysis of the ink made it fairly clear it was a forgery.
This news is just that a more detailed analysis has been done, proving the map long believed to be a forgery was definitely a forgery. But the map was never really considered evidence of anything in particular; it was always questionable.
Samuel Eliot Morison, The European Discovery of America: The Northern Voyages, notes to Chapter III, "The Norsemen and Vinland".
Otoh the deception lasted 100yrs.
Not really. Pretty much from the inception, the academic community was strongly skeptical of its authenticity. While Yale has only recently admitted that it's a forgery, that's probably due in large part to reluctance to admit that they spent a lot of money on a pretty clear forgery.