Showing uncensored boobs shouldn't be enough for Erotica tag though, thats still just ecchi which is Suggestive at best, not even from the mangadex guidelines, work isn't a smut for a erotica tag smh
2.2.2 The content rating for a series is based on the highest level of sexual content in the series. In general, entries that focus on sex or contain uncensored sex scenes should be marked as pornographic, entries with heavily censored or non-explicit sex as erotica, and entries with light exposure as suggestive.
Whoever keep changing it to erotica is scared of boobs, or mangadex have to revise all those works that are tagged as suggestive because there is alot of works that flash their uncensored boobs with partial nudity
This in comparison to yowa yowa sensei is super tame, because this so far isn't going for a sexual theme unlike yowa sensei, specially with how some of the later raw chapters are