From past experience, I feel removing and reclassifying anything in this game is asking for frustration down the road, because the Devs have built a system based on their roadmap, which is still evolving.
I would rather keep the school uniform category as is (see reason below), and add a new category for indoor Home wear. Hence my wish list in the other post Add new Outfit category in CAZ as “Home”
Considering that the school system is getting an uplift, it is likely that the school uniform will be used by age groups children to adults. Children to Teen as students (school to University) and Young Adults and Adults as faculty members in the schools/universities. (In my country, not just the students, even some schools and college faculties have uniforms). So let the school uniform category be as is, and add a new category for indoor outfit.
Those who do not want to use school uniforms, can customize that outfit as they see fit, perhaps same as outdoor wear.