The blog post is misinterpreting the OGL, IMO, because it is interpreting the 1.1 OGL as an "update" to the OGL rather than a replacement like the 4e GSL.
I think people are getting hung on the "OGL" and "open" words in the title of the 1.1 OGL, but it is anything but open, and its function is completely separate from a true open license. Its wording is much closer to the closed off GSL.
When people are framing the new 1.1 OGL as an update, that simply isn't true. Its a replacement, and one that requires people to buy into the idea that its just an update, rather than the end of open content for dnd.