Hello, looking at the conversation in context Sloth was referring to your username being a larger issue than being unable to be called princess in the game. No one was threatening to ban you over your username or your complaint. You are wrong about succubi though, they are inherently sexual demons and in most media are depicted in an NSFW manner (But they have occasionally been referenced tastefully in cartoons before, usually without invoking their full context).
As was pointed out in the discord discussion, titles are not permitted in names. Although there is the possibility for support being added for titles in the future but mainly for roles. (This is primarily done to prevent abuse and keep player names shorter).
In regards to your complaint about Sloth, none of this exchange was unprofessional or unwelcoming. Sloth was simply bringing up that your username *could* be considered not safe for work and could cause issues. No one is going to kick you for your username without giving you a chance to change it or explain yourself and to be honest I personally don't think it's a major issue.
The shrug emoji in particular is a common and inoffensive way to signify that you don't really care either way and isn't unprofessional in the slightest. As someone uninvolved in this discussion (Who is also Trans, so please don't try to weaponize your identity like that) none of this conversation reads as threatening or unprofessional and I'll be honest you seem to have some preconceived notions about Sloth.