It sounds to me from this section of his Guardian interview about the book that he went in with an open minded, balanced approach, as you would hope an author would:
”What led you to the novel’s transgender storyline?
I just thought it was such interesting waters to go into. We’re all asking fundamental questions about identity now that the things that defined us are slipping away. It’s complex, moving-picture stuff. You don’t know how much of it is a distraction to keep us at each other’s throats politically: if trans women compete in athletics, or if they’re barred, it’s not going to change the fact that lots of people are going to die because everybody’s getting fucked with their heating bills over the winter. It’s obviously difficult waters to go into because everything has become so shouty. We had a trans adviser on the book and I was dreading it. I thought, this is going to be another layer of censorship. But it was incredibly educational. I learned a lot.”