Not once have I encountered a trans person on a dating app who wasn't 100% transparent about it. Some even asked me after matching, "you're aware that I'm trans, right?" just to be sure.
There's no logical reason to falsely pretend to be cis on a dating app to get matches. If someone's cool about it then it's better to know up front, right? And if they're not, then you probably don't want to waste your time on them.
The "justification" for this app is just bigotry, plain and simple. Fuck TERFs.