I'm all in favor of the sign.
To me it just looks like somebody's trying to give a heads up to people who might be freaked out by this sort of thing without prior notice.
I'm pretty sure somebody's 80 year- old church- lady grandmother on her way into the bathroom to powder her nose is going to be freaked out by a 6 foot 4 transvestite with 5:00 shadow regardless of whether or not that's the "right" reaction to have.
I think anybody who sees a problem with this sign is expecting way too much way too fast.
People who are used to certain things being one way --- because that's the way things have been their entire lives--- are going to take a while to get used to these sort of changes. I think holding that against anybody is a bit nearsighted.
If we're supposed to be trying to get from one place to another as far as all this goes, then as far as I'm concerned this sign might as well say "Warning: bridge under construction".
I was going to Like but saw the transvestite part. I agree with what you're trying to say, but the issue is the stereotype and misinformation about transgenderism, passing, gender vs. sex, and discriminator terms like transvestite applied to transgender and associating how they look as a defining factor of who they are (if they look male but say they're female, they're lying or misinformed...type of thing [unfortunately, that RF conversation never did end well])
I think it should be more "this bathroom services both sexes" and nix the reference to gender, transgender, and anything like that.
But we do need to change the stereotypes, education, and make words clear and understandable rather than jargon (i.e. instead of saying "assigned sex" just say biological sex, type of thing). It will take time. Education is a huge one and patience for people to adapt their views or change them for the betterment of other people would help as well.