In IT, We've been calling them gender-benders for decades.

Yep. Decades with electronics. Gender changers have always been a thing and often necessary.

Now, with humans? You may have a point.

I've been messing with electronics for over 40 years, both as a hobby and for work, and there have always been adapters and dongles known as gender changers.

There has also always been only two genders for plugs. Male and female.