Whether it’s copyrightable or not is a legal question, and Schwartz isn’t a lawyer. And the answer has to be the same for everyone, not just Sun. Now, that might be an “implied license” or “estoppel” argument—even if it’s copyrightable, you can’t enforce it now because you led everyone to believe they could use it for free.
Yes, of course. My point is that Schwarz isn’t an expert in copyright law, nor can his individual opinion be dispositive on a question of law that affects everyone.