You'd be better suited just having a user select that they are comfortable dating a trans individual because it will likely come up very early in the dating process anyway.
Forcing someone to identify as a gender that doesn't make them comfortable is just going to result in them not using your app and is frankly kind of a dick move overall. Your suggestion would just create an app that was suited for chasers, not trans users.
European Starlings were introduced in the US about 100 years ago by a misguided fool in Manhattan. They are invasive, but absolutely everywhere around the US at this point and that's definitely a European Starling fledgling.