I mean, I can't actually explain it rationally, either. I'm asserting that I don't have to - that it's as acceptable as stating "I am a woman." I don't understand what the fundamental difference here, because they're both assertions about myself (well, I'm not a woman, but I'm keeping the article's quote for emphasis). I'm not making an assertion about the value of the trans person in question.
I don't understand this second avenue, either. You seem to be essentially saying that either new information is not allowed to change how you act, or you have to justify it. All information is, at some point, new, so the former is clearly unworkable and the second just leads back into my first paragraph.
I'd say what I'm primarily pointing at is that you only have to justify it if the information isn't relevant to the issue "at hand", so to speak. In the hypothetical scenario, you've got a post-op transgender who has no baggage from the transition process and will not develop any in the future. There's no connection, behaviorally or otherwise, between their previous gender and their current one. No impact on their current behavioral patterns or aesthetic appeal. Et cetera, so forth.
In this case, who they were in the past has no impact on the present and will have no impact on the future. In this case... I'm asking
why would it matter and, from the other angle, how is it fundamentally different from swapping "previous gender" with "<Insert racial ancestry>"? From a similar angle, why would your partner being grossly overweight (or thin; whichever direction turns you off. Pick any aesthetic consideration, really.) or a mostly-brainwashed <insert heavily disliked ideological group> in the past matter
now, if it has no impact on the present? Ties were cut, weight was loss/gained, etc., so forth, so on. If they're what you want now and the past isn't going to be butting into the present, why should it be considered?
If you're discriminating against them in the present (by removing them from romantic consideration) when that previous state has no connection to their present state, you're no longer discriminating against
them (which is fine, in this case, and for a romantic partner. You're allowed to have personal tastes, of course), you're discriminating against that previous state; their transgender history, their previous weight, their ancestry, etc. You've stepped from the personal to the categorical, no long judging them as who, but instead as
what.
Depending on what that "what" is, that might not be a bad thing, exactly; that's why I mentioned aesthetics specifically, as most have very little conscious control over what they find physically attractive, but why less fundamental/arbitrary measures (such as history or achievement, ferex, especially when one or both has no influence on the present time in question.) I would call into scrutiny.
I mean, I'm essentially arguing that you have an impression of somebody, learn that impression is wrong, and are not attracted to the updated impression, and that there's nothing about this that is particularly wrong - although you can certainly handle it wrongly.
Yeah, that in itself isn't necessarily a problem. It just depends on what causes the loss of attraction. You might be unable to control it, but that doesn't mean it's still not unjustified prejudice, if it's relation to a subject that prejudice requires justification. I'd call post-op transgender in particular a case where justification is required, because there's no present or future difference between them and your desired gender (other than reproductive capability, they're now identical.) and the past is a non-influence on the person in question.