I’m going to make a longer comment with some of my more personal thoughts later but the one part that caught my attention initially was the ~15 years part.

Now I’m not going to be a stickler about precise time ranges but certainly in the 90s there were significant discussions about male/female gender roles.

While discussions about trans/gender identity topics only really picked up steam in I would say the last ~7 years these sorts of things were pretty common discussions in feminist academic circles for quite some time even before that, so it’s likely that the discussion would have happened sooner or later, even if in a different way than it did.

Last comment about timing - I suspect politics had something to do with it. More cynical analysis might say it’s been used as a wedge between the American right and left (as passion for fighting over, say, gay marriage has lessened) and there’s a cynical argument to be made that both parties actually want it to be a contentious issue because it helps then to differentiate and appeal to their base in different ways.

Some equally cynical analysis from the left specifically associates the rise of gender as a topic (and several other social issues) as a way to distract the new left from economic issues (ex: occupy Wall Street, Bernie Sanders-esque stuff). While I don’t think most on the left would claim the aforementioned social issues are unimportant they would claim that they’re of secondary importance when a great number of people are struggling just to get by with the situation only slowly getting worse.

I’ll make a separate post later on my personal feelings more on-topic.