The HN headline edit obscures the point of the article, which amounts to an argument that prototaxites were basically fungus. It's like taking an article that says "dinosaurs are related to birds" and changing it to read "the ancestors of birds are related to birds." It reduces a new, interesting claim to a tautology which is not, in any way, what the article concerns itself with.
Here, the descriptive, sensible word 'mushroom' is replaced with 'prototaxite', a word that is meaningless to (let's be honest) most casual visitors to this site.
Accessibility and meaningfulness are casualties in the war on interestingness.