Yeah, that was rather disappointing. I wouldn't have minded that the Linux driver had been used as an input, allowing Claude to reason about the functionality and interface. That seems like a reasonable approach.
The "only built for Windows" is also a little dubious. Technically I suppose HP could have just intended it as a Windows printer, but the driver clearly already exists in CUPS, which Apple also uses, so porting the driver isn't an unreasonable thought.