World of Ice and Fire also says that there was an Elmo, Grover and Kermit Tully. I realise he has always made references with some of his names but that just felt more than a little on the nose. I wonder how much of that stuff was Elio and Linda.
George put his name on the front of the book and undoubtedly wrote at least some of it and had the final editorial say so IMO it is all on him.