well, one of my best friends is transgendered. I knew her as a man for a decade or longer then as a woman. My husband has been friends since he was 8. I can see a
resemblence but I don't think it's the same thing.
As was proved later in DS9 in a court, a trill is not the same person they were in previous joinings because they are two personalities and lives joined.
a transgendered person is still the same person. The packaging is just a little different. And the pronouns. Belive me, the pronouns are the biggest issue for other people. lol
You're right, it's definitely not the same exact thing, but I can see how both Trills in Trek and transgendered people in reality face similar issues.
As a transgendered person myself, I found it nice to see at least a superficial comparison, in particular, the way everyone has to slowly adapt to a big physical change in someone close to them. In that sense, I guess Star Trek succeeded in hitting the right emotional strings in me over an issue I directly face, even if it wasn't entirely intentional--I'm sure that's something that would make the writers happy regardless.