I too know of an aussie pilot who decided being male wasn't his thing. She ended up being victimised by a number of other pilots - ultimately resulting in her 'demotion' (for a short while) until the 'powers that be' backed off and realised the trouble they were in.
In reality - and I think it's the same almost anywhere in the UK/USA/AUS...
Making this personal choice should NOT impede your success when applying for the job.
Unfortunately, the personal connection you make with any recruiter (who, granted, is human too) - is more often than not, distorted by the applicants race, physical appearance, sexual orientation, and GENDER.
While I admit, recruiters are human too (so i'm told anyway) - they are likely to assess you not just by what the airline dictates, but their own personal experiences and education. (It's not right - but there it is!).
By the law, you should not be treated differently - that said, it's not hard for the recruiter to lie, and say that you didn't get the job because of your 'attitude' or the 'way you answered a question'...
That's the reality - unfortunately - and until things improve (and you can force the improvement if you've got the cash and the time to challenge) - thats the way it is.
For what it's worth, a bunch of girls I work with decided they should challenge on the grounds of ageism - and they won! It's a shame they had to - but even they admit justice is not free.