You claim that nobody is hiding information about their genitals. But while we can debate the semantics of "hiding", there are certainly lots of people who are not being open about that information. And I am arguing that the world would be a better place if everyone was just open about their genitals (and indeed their hormones).
It shouldn't need to be a big deal. There's nothing shameful about having genitals that don't match your gender identity (and that would not put me off dating someone).
Are large numbers of cis people really finding that trans people are contributing substantially to their difficulty in finding a suitable partner? I see no evidence of it. This concern is almost always raised in rhetorically heated threads about trans identity, in the service of a particular argument – but almost never in threads about dating.
I agree that the general prudishness of dating and dating apps (especially for straight dating) makes this all more difficult than it needs to be. But as far as trans people are concerned, all I really see here is a lot of unnecessary worrying about improbable hypotheticals that aren't even that bad if they actually happen.
Very few trans people are likely to do a 'surprise reveal' because they know all too well that this can have disastrously violent consequences in a heavily transphobic society.