Mr_Homn suggested and you agreed that it didn't sound inclusive of transgendered humans. I don't see how, as I said there are likely transgendered individuals from many species. Data's phrasing is all-inclusive. I'm sorry if I misinterpreted what you meant.
To me, data's phrasing seems to imply that the only invited transgendered people are from non human species. As if either A.)transgendered humans do not exist or B.)they weren't invited. If I was transgendered I might be a little annoyed to be grouped as a non-human.
I get the feeling that the writer may have been trying
to make the star trek universe seem more inclusive to LGBT viewers, but I think it was executed poorly due to the phrasing. Saying "ladies, gentlemen, and transgendered guests" would have been more inclusive and respectful. But that would have meant one less data-comic-relief moment that they seemed to be unable to restrain themselves from on so many occasions.
Yes that would have been better, but I still don't think it necessarily excludes humans, because as as I said it's not an exclusive human thing (I would assume anyway). It does exclude beings with more than 2 sexes though, luckily there were no Andorians there.
It also never struck me that was meant to be a comic relief line, it felt out of place considering it followed Picard joking twice.