@teruhashiclone
No, they're transition stories but there was no gender dysphoria prior to that point; they just wake up one day and then there is some potential adjustment period and then they live their lives.
It would be a trans story if they were actually transgender or gender dysphoric prior to that point and then have their wish magically granted, perhaps; that's different.
The appeal for most about genderswap stories is that the character didn't have such a prior wish or dream; the appeal for many is often the confusion at it and the adjustment period. The appeal is that the character never gave it prior thought, suddenly wakes up as the opposite sex, and all the comedy that comes from the unfamiliar situations. If it be either a slow transition via hormonal means, or the character spent years præparing for it, it's obviously not as funny.
Personally, I don't really care in this case though because it happened years ago for this character; it's not as interesting as say
Boku Girl, where it's a new experience for the character, or
A Lazy Guy Woke Up As a Girl One Day which inverts all the
clichés with the side characters expecting this confusion but the character being completely disinterested in it.