It seems about right. The whole point of the crown power up was to establish the relation between Peach and the Toads, explaining why does a normal looking human like Peach governs a species that doesn’t look like her. Before it seemed that Peach was a princess because her magic powers gained her a mass of followers, but now it’s like a Gerudo thing where once every x years a single perfect humanoid princess is born.
The crown is just a temporal power up that helps the species to reach their perfect state, turning Toadette into Peach.

The only other ones who should be able to use the crown are the other Toads given they have no specific gender, but I can see why they won’t go for that route.