Verdict: If dealing with Java Generics was a relationship type, this text is what you would call “gas lighting”. Reading the article is a poor use of your time, you can skip it.
Regarding the article itself:
Most of the points made hinge on the reader being completely unaware of the CLR existing and various types of logical fallacies that are liberally sprinkled throughout the text.
I find it particularly intellectually dishonest to pretend that “erasure vs. reification” is a black-or-white decision … in a language that has used partial erasure since version 1.0. It has always been a range between erasure and preservation of types – proponents of reification/specialization simply ask to extend that range slightly further.
With that, most of the “what if” concern trolling in the article collapses.