I was claiming it could be left implementation defined instead of unspecified. That way, code for particular platforms could be evaluated in different order, but it would always be deterministic for a particular compiler.

The optimized evaluation order would depend on the situation near at the call site, not the architecture or platform.

The GP that my post was replying to was claiming it was arch dependent, and I was pointing out that, if it had been, they would have likely not left it unspecified. So, I think you and I are in agreement.