It's obviously extremely wrong, but their incentives aren't for being sticklers on accuracy. It's on being sensational.
If this guy is correct, the edits are sufficiently spread across different articles for him to have touched 1/3 of them. Still obviously not the same as writing, but it puts the headline in a slightly less absurd light.
[0] https://www.quora.com/Who-is-Ser-Amantio-di-Nicolao-of-Wikip...
[1] https://www.washingtonpost.com/lifestyle/magazine/meet-the-m...
Perhaps this guy's contribution count represents one-third of a top-contributors list, and the author conflated that with "all of Wikipedia" out of laziness? Curious that "Steven Pruitt" (or any usernames that look like they might be owned by him) doesn't even show up on any of Wikipedia's own lists:
https://en.wikipedia.org/wiki/Wikipedia:List_of_Wikipedians_...
https://en.wikipedia.org/wiki/Wikipedia:List_of_Wikipedians_...