Genus means grammatical gender. He is telling us his pronouns and I'm with him on this. Saying "my grammatical gender is masculine" makes a lot more sense than saying "my pronouns are he/him". Like, who's going to mix pronouns?
His grammatical gender is masculine and his hat gender is fabulous. That's the highest fez I've ever seen and the longest tassel. Well played, Sir.
Does that literally means use she and they in each appropriate context? I've always interpreted that as meaning they're ok with one set of gendered pronouns and/or neutral pronouns, not that you're expected to contort pronoun use to neutral only in specific cases.