Fascinating stuff, although I do not pretend to grok the maths.
On the one hand, seems to offer formulaic approach to creating effective interventions to curb online hate-speech. A more functional approach than hand-wringing, and more effective than "thoughts and prayers" platitudes following IRL consequences of hate-speech.
On the other hand, who decides what is undesirable hate speech? For instance, I could see both of the US abortion debate "sides" (yes, I know, there are more than two) claiming the other is wrong, is promoting hate or harm. Each side might feel itself justified seeking to intervene to prevent spread of an ideology.