I disagree with your last statement. Is promising to change not evidence of the motivation to change?
Some people lie about their intentions or don’t plan to change as quickly as expected, absolutely. But to assume everyone who has promised to change won’t feels unfair.
No one is really “qualified” to weigh in on someone else’s gender identity or expression. Although, everyone is welcome to support and share their experiences while they navigate their own (or their partners) transition.
Look into the various “blahaj.zone” instances if you want some already established communities.