ETEWAF stands for Everything That Ever Was, Available Forever. Basically, Oswalt argues that having massive easily-accessible archives of media going back decades is actually hurting the entertainment industry, because every time something new comes out, it's compared to the best of the best right away. Not only does it contribute to the "everything _must_ be part of an established franchise" attitude as described in the article, but it also hobbles new entrants in franchises by setting impossible-to-beat standards. It hurts new entrants in franchises because people treat new movies with the expectation that if it's not better than the best movie in the entire history of the franchise, it's not worth watching. And, getting back to the article's argument, it hurts non-franchise works because if something doesn't tie in to an existing decades-old pop-culture saga that everyone's archive binged on, it's not worth bothering with because it won't have the emotional connection that something in a franchise has. It's a double bind.
Another consequence is that you can't do anything unironically anymore. Every new entry into a genre has to make fun of and subvert genre tropes. They have to have characters snark "Oh, this isn't like the movies, [creature]s in the real world don't work that way!". You can't just do a straight-up action-adventure movie now because they all have to be half-comedies where the cast mocks the genre tropes as they unfold.
As much as I love being able to do huge archive binges of my favorite things, it's ultimately going to kill the ability to produce anything new. Honestly, I just want some straightforward pulpy entertainment where nobody cares about either fitting in with past material or defying past material.