The short answer is ‘sort of’. Because SFF is genre fiction, it inherits and works through tropes and motifs from past works and sub-genres (many of which were implicitly partriarchal, heteronormative and based on the values of ‘white’ societies). In order to represent alternative viewpoints, therefore, modern SFF has to work very hard to subvert those past norms. Sometimes the subversion is successful but, often, the subversion goes unnoticed by the reader and the reader considers the book poorly written or unintentionally cliched. Tricky. Want to read about the subject in more depth? Then have a look at the new Luna Press collection of essays on the topic. I’ve got an essay in there (based on my PhD), and so have the likes of Juliet McKenna, Kim Laikin-Smith, and many more: https://www.lunapresspublishing.com/single-post/2017/04/01/Ten-Strong-Voices-Join-The-Luna-Family
Gender identity and sexuality in current fantasy and science fiction: do we have a problem?