Fortunately, any well-designed (from a back-end perspective) site should have no problem presenting the relevant information both on the relevant page and on a catch-all FAQ document. This would allow the site to elegantly handle everything properly.
Source: Working at a startup with a wide audience. The email consisting only of the subject line "WHAT IS PASSWORD" was not the least-savvy email received.
I know a lot of my peers would know what FAQ means and what a password is. Even some of the "less" tech savvy people. But late adopters who are still using 10 year old PCs usually don't know.
Before I hear claims of ageism, it is just a fact that a higher percentage of the older generations don't know how to use computers. It isn't ALL of them but they didn't have the benefit of growing up with computers as a tool, to the point where they become second nature.
I understand you may be defending the author but maybe think twice before you try to discredit someone so quickly, without any knowledge of their background?
There is nothing wrong with questioning credentials when things get down to a he-said-she-said. Your comment provided no reason to think you had anything more to back up your claims than the usability studies of the OP. If knowledge of your background is going to be important, that might be something you should mention.
As mentioned in the post, the claims are indeed based on real studies: observing users as they perform prescribed tasks in a usability testing lab.