I wonder if that was some inspiration for Iain M Banks' Culture series, in which citizens are able to change their sex at will over the course of about a year. Banks wrote specifically about what this signified for civilisation:

> A society in which it is so easy to change sex will rapidly find out if it is treating one gender better than the other; within the population, over time, there will gradually be greater and greater numbers of the sex it is more rewarding to be, and so pressure for change - within society rather than the individuals - will presumably therefore build up until some form of sexual equality and hence numerical parity is established.

http://www.vavatch.co.uk/books/banks/cultnote.htm

I imagine so.

The Culture books started being published in the 80's and Varley was writing short stories about how sex changes that were fast, cheap and easy would effect societal gender roles in the 70's.