In this article, the author writes about Nintendo fans using 層 as a suffix:
And, at last:
In Weblio's definition, the indication of 層 as something related to position, status and class becomes clear, and there is even an example using the word 「ファン」 to describe a group/collective/assortment of people.
I can kinda get the usage of 層 in the first example here, where the author refers the "the class of fans which are the most passionate", as well as the second and third where what kind of class is referred to is also clear. But the fourth one bugs me, which 層 exactly does he want to refer to here? Given the context, we know it's those "passionate kind of fans", but if that were to be a single phrase, would it still make sense?