If a young boy takes hormone blockers which arrest normal genital development they will be left with insufficient material to work with in future surgery.
This effect is very well known, but is swept under the carpet by TRAs in favour of the argument that if a child doesn't go through a male puberty, they will superficially 'pass' better as a woman.
TRAs, many of whom seem to be obsessed by sex, apparently have no qualms about encouraging young people to transition very early and consequently having no sexual function whatsoever.