You’re making big assumptions. Considering that Mobil had already gone to a magnesium blend for LSPI around 10 years before the test became part of the spec, and the fact that they were one of the companies pushing the new spec, it’s highly doubtful their oils were substandard. As a matter of fact, your point that the labels did not change after the LSPI test was added, is a pretty good indication that the oil was already formulated to include LSPI testing. Unless you’ve got documentation that either the oil additive makeup has changed, or proof that the oils you claim do not meet the 229.52 LSPI test… you’re completely off base and beating a dead horse while you’re at it.
There’s at least one other thread that covers how advanced Mobil’s oil makeup was back when the SN+ & SP requirements came about… they were driven mostly by XOM’s development.