...say gay historians.
The point of this article is that the gay identity is a recent phenomena in Western culture, appearing about 150 years ago. Prior to that, of course, there were individuals who engaged in same sex relationships, but didn't identify as belonging to a distinct group and certainly didn't claim to be "born that way." This admission undermines the entire "civil rights" claims of gay activists that their sexual proclivities entitle them to special treatment.
While the article never uses the word "choice," I found that concept implied throughout. So these historians, many of them active in the LGBT community, recognize that people make sexual choices. I doubt if they regard any of those choices as wrong or sinful, but that simply points to our modern culture of anything goes.