The bulk of the link is devoted to an analogy, which is that variants are to folklore as remake and reboots are to Hollywood movies. The thing is, that analogies are only as compelling as the resemblances between the things analogized. If they really are the same, the analogy essentially becomes an argument from causality.
Variants are the authoritative
local versions of a story. They are only local stories because folklore is oral and cannot be transmitted accurately. Remakes and reboots are not authoritative
but compete with other versions of the same story. This is possible because Hollywood movies are mechanically reproduced, i.e., perfect copies.
As you can see, Newitz has tried to argue an analogy between things that are opposites, not the same. This would be incredibly stupid were it not for the self-serving goal of justifying io9 puff pieces for remakes and reboots, rather than making an honest argument.
There is also the truism that nothing is original. A truism is a statement that is true but trivial. This is a truism because the real question is not, was this story completely unlike what has come before? (Never, of course.)
The real question is, are the elements from other stories and life put together in novel ways? This kind of originality is quite common to some degree even in derivative stories. A few stories are highly original. Often these begin a subgenre, or even a whole genre of stories, that imitate them. Remakes and reboots, by recycling even the names, character, plots and themes are not even as original as derivative stories. But, like Shakespeare, they have still have as much originality as the novelty of their dialogue allows. In practice, we know that most are not really very original.
The claim that Buffy is the same story as Dracula is of course BS. Mina Harker plays the role of an unfaithful wife whose very blood is corrupted by her adultery (think syphilis.) Buffy is not Mina. This is not just obtuse, it's a flagrant imposition.
Lastly there is an element of faux-populism in associating the desire for originality with Modernism. Shakespeare may have recycled plots, but he (almost)* never recycled verse or prose dialogue. Unlike most Hollywood remakes and reboots, his new dialogue was both highly original and a great improvement. Very few other Elizabethan and Jacobean (or Restoration) playwrights remade or rebooted plays. Nor was there any demand for remakes and reboots. Instead there was a relentless demand for as much novelty as could found. Now that was four hundred years ago. So much for the Modernist innovation in valuing originality!
There are cases in drama where originality was devalued, mediaeval mystery and morality plays or (I think) Chinese opera. That has nothing to do with Newitz' thesis.
Obviously nothing Newitz wrote was worth reading, much less the labor of rebutting. But it is irritating to see such shameless BS held up as rational thought.
*Shakespeare directly quoted Marlowe in As You Like It, so there's at least one exception.