That article also admits the author "did all kinds of twisting and rationalizing and ignoring certain things in order to make my theories fit with the continuity as originally established" and even he can't explain away the timeline of "Sins Past" glopfest.
Well, yeah, when discussing when she was pregnant and had the babies, but the rationalization as to when and why she would have sex with Norman was based on specific events from the comics, and not just pulling it out of his ass. It's not too much of a reach to fit Gwen's dalliance with Norman into the events listed.
For the record, I'm not a huge fan of the storyline either, but my problems are with how it convolutes canon as opposed to it ruining the characters of Gwen and Norman (and I thought the age-accelerated twins as supervillains bit wasn't handled that well). Personally, I thought American Son did more damage to Norm's character than this.