They didn't even lead up to it gradually. We thought they might start by hiring a condescending little prick to sprinkle judicious praise on a few of the more assimilated examples, but no. (Dave Itzkoff didn't come along until years later.) And the world didn't end. In fact, the apocalyptic review didn't seem to change much of anything, but I no longer would be surprised by "mainstream" acceptance.
So I'm a bit blasé about The New Yorker's Science Fiction issue, but I like it. So that's how Colson Whitehead got to be like that (specifically writing The Intuitionist, which I love). I guess the big surprise was finding out that China Miéville survived starting out with Alfred Bester's Golem 100 (the cruelest Bester parody, as Slapstick is the cruelest Vonnegut parody). Miéville noted the "disrespect for text" and kinda liked it. I figured it came from not being able to do it anymore; before Viagra, there was a lot more disrespect for sex. (I hasten to add for those who don't know him that China Miéville does not write like someone with disrespect for text.)
I also noted one of my least favorite things about The New Yorker: the difficulty of finding article amidst the advertising pages. Tom Wolfe's famous attack on the zine was vicious, one-sided, and gratuitously personal, but he was not entirely mistaken when he said that the text is a gray background intended not to be too distracting from the important part.