Whilst transitioning females to males have the same objective as vice versa, there is nevertheless a difference. As far as I'm aware, there haven't been any incidences of transmen presenting a problem or threat to other men in changing rooms/public toilets. Neither I imagine, if a transman were to enter the sporting arena would they make it impossible for a natal men ever to win in that field again.
Whilst the majority of transwomen will be mindful of any potential threat that a cynical minority of transwomen could present to women/girls in vulnerable spaces. Most of us here on GN on such a subject will be aware of the individual who goes by the name of Karen White. Furthermore, there is a very aggressive element in the transwomen lobby who are determined to fight (literally) any woman who goes against their ultimate aims, almost as it were to prove a point that they can trounce the desires of a majority of natal women to feel comfortable in what they have previously found to be safe havens. In some respects the overt aggression such people display, could be deemed as a characteristic more likely to be found in the male of the species.
I may be wrong but it appears that these battles go one way, men transitioning to women rather than the other way round, so yes Paddyanne I doubt whether the two young people. you know will be a threat to anyone. It isn't prejudice for women and girls to want to keep personal spaces such as changing rooms, toilets, women's refuges and prisons places where they may encounter, because it hasn't been unknown, to all intents and purposes a person who presents as a woman but has predatory male tendencies, hence my reference to Karen White.