The GM-LL specs are correct for the 9-3 and should be followed. That said, especially given the change to lower OCIs in subsequent years, that spec may or may not be important. What IS important, and apears to be a prerequisite for the LL oil is to meet ACEA A3. While A5 is the long drain spec, my manual explicitly states that if the right LL spec oil cannot be found in a pinch, that the correct plan of action is to use an A3 oil with the right viscosity.
I buy that... That said, I have run Amsoil SSO, which is not A3, and got very nice UOA results.
However Id recommend ACEA A3 at bare minimum. The LL spec oils are very good, Id run them and not bother thinking about anything else.