I sort of wonder if that taboo even applied to aliens. I mean, it appeared to be part of the overall effort to prevent the creation of a Trill ruling class that would create permanent associations, transcending mortality. I forget if it was ever stated, but I'd reckon that there's a prohibition on passing down gut-slugs through family lines as well.
Hmm....
I LIKE the way you think, sir!

Outside of Trill society, when banging Klingons and humans and such, the taboo wouldn't serve much purpose (it might still be enforced, but it would be irrational).
Agreed. This is where "Objective Rule of Law" sets in. We must follow the law, but also look at the spirit of the law, to determine how to interperet it.
(For example: take the Constitution. Many times the darn thing is a little vauge. Thus, determining the spirit of the Constitution involves reading the Federalist Papers, the Declaration, and the other writings of the Founding Fathers--basically knowing the principles the USA was founded upon....)
(Of course, this sort of analysis might undermine the anti-discrimination, "plight of the homosexual" message of "Rejoined," since there actually are good, rational policy reasons behind the prohibition--then again, it's what we would also consider a liberty interest, like pursuing one's sexual orientation, so I suppose the message might remain intact.)
Well, remember, the writers swore that that wasn't the message--that the only reason they made Dax's former love a girl was for ratings. But...that's splitting hairs....