If you read properly the text you quoted, it's not about usernames alone but content in general. I'm also pretty sure the mods are applying these rules in the same way many other games and sites apply rules like this. Presumably naming your character "Pirate" or discussing fictional gambling is ok, but linking to gambling or piracy sites would not. You seem to be making a really big fuss and seeing loopholes were there are probably aren't any in practical terms.
I do think certain names and content would really cross a line even if they're fictional, such as child porn, slurs, suicidal ideation, etc. If nothing else it's rude to expose people to this if you don't know what their hard limits are. For some people it's not just being "hypersensitive", it's about not wanting to deal with real life problems they may have experiencing when trying to have fun and play a game.
The game itself has some aspects that I don't think have aged very well but of course I don't think that's the Homecoming team's fault. I would just expect some good moderation when it comes to interactions between players and some consideration to try to make even "dark" missions and plots dark but not offensive if they ever make new ones. That doesn't mean shying away from the fact that crime and villains exist in this game and that you can play gritty characters, just making sure that people aren't roped into situations that distress them in real life.