Every quote of that manifesto sounds fake. Why would a transgender person use a gay slur to describe white children? And what person about to go on a homicidal rampage would censor the word cracker which doesn't hold nearly the weight of most racial slurs?
Sounds like something made up by people like Steven Crowder
Based on the excerpt the censoring is likely learned behavior from online text communications. Some younger people have gotten in the habit of censoring on their own to get it through content filters and still convey their message.
... just because you don't like how things sound, doesn't mean it's fake. That's some MAGA logic. This story from the outset seemed like this scenario was likely. Wild, in America, even ultra leftist can be school shooters. Absolutely shocking.