Free oil changes is US only.
Most people buy in and out of luxury cars long before the engine is even approaching any serious age, so I don't see the planned obsolescence argument. Cars are staying on the road longer than ever now.
Your tbn is low and metals are high for the interval IMO. Although in general, UOA's don't speak to the ability of the oil to actually lubricate the engine. 91 octane has a better chance of causing more wear than 12k-15k mile oil changes IMO. Detonation is what beats up the bearings and you will not run the best timing on 91.
Although again, there has been some hearsay that the 08 bearings are even tighter than the 09s, and therefore could wear worse. You also don't know how the previous owner treated the engine.