At this point the most likely answer is they don't want SEGA to know how much we hate it becuase then they would be forced to change it.
One potential reason could be, from what I've read from other companies who have made similar decisions in regard to censorship or general design changes, is that Japanese and Korean companies are now "aware" that there's a group of people in western world who have a problem with lolicon/shotacon but don't understand "why" they have a problem with it. This is leading to situations where loli type characters are being aged up or removed entirely from completely SFW products where they aren't being sexualized at all and adult aged but small breasted girls being censored in full pornographic titles. They don't understand why some westerners are upset, just that "westerners are upset about loli characters" and are removing them in their entirety from a lot of products to avoid the possibility of social media backlash or more likely, future legal issues.
There's also a group of people who believe that lolicon/shotacon is illegal in some places right now and/or may become illegal in more places soon, and while that may be true, there's absolutely nothing in PSO2 that would get Sega in legal trouble anywhere in the world. The problems are: 1.) They look at those of us who want to play short characters in a video game as inhuman monsters who only exist to hurt children and think that no one will care if they bully us. 2.) They don't care enough to do the legal research to see that nothing in PSO2 will get them in trouble anywhere in the world, again adopting a completely heartless "who cares about a bunch of pedophile's feelings" mentality and thinking it would be easier to just say "screw you".
And society completely justifies them acting like that because that's how media has taught people to view pedophilia, who they're viewing all of us complaining as. "If you want to make a short character in this video game, that means you're a pedophile and if you're a pedophile that means you're a ticking time bomb who is going to ruin a child's life and that means we can treat you like dogshit and no one will care". It's a toxic mindset that comes from a place of bigotry and a lack of empathy at a time when everyone is screaming from the rooftops for understanding and tolerance of each other. It doesn't matter if you intend to make a character who looks like a child or not, or if you have those feelings at all or solely towards fictional depictions, that's the justification they're operating on.
It's awful. And this isn't me defending any sort of illegal act. This is me saying "being a bully makes you an asshole, regardless of who you're bullying".