I don't know what you intended, but phrasing it that way is a literal denial of the existence of trans people. Transitioning is a realization of who the person has always been, not a "life choice" to suddenly be someone different.

Denying the existence of something and not wanting something to exist are not exactly the same thing, but there is a lot of overlap. Again, I don't know what you intended, but many people pointedly use the word "choice" around this topic. Your phrase would be more accurate if it said "they may not agree with different life experiences" or "they may not agree with different lived realities". Those are decidedly more cutting than the phrasing you used.