Indeed the term has been used for decades and sure, many people have a common understanding of the term. But, many do not. It's rarely used in its original context. In the decades that I have been moderating I can tell you after seeing hundreds and hundreds of the use of the term, many do not share a common understanding.
There is no re-shirt "process" and one does not "achieve" a red-shirt. Those references confuse "some" people.
And, as I stated in my original post, I believe I am an outlier in my position.