I would say it's a safe bet that a fluid an independent bottler offers as certified API, or other org cert., that the formula was a fully formulated, pre-certified, package they purchased from a major oil co.
Amsoil provides some certified oils, and I bet my eye teeth these were purchased packages. Their high-end products carry no certifications, as they have probably tweaked the packages, or fully formulated, causing the need for re-certification testing. Their R&D and testing may well take them in the direction of a superior fluid, but the cost of re/certifying these products would probably be prohibitive to them.
(hence many "meets or exceeds" statements)
And this is just more of MHO, but I also feel that this situation is exactly what prompts some of these bottlers to downplay the certified sector of their lineup with their marketing.
They probably only carry these few certified products to satisfy some of their customer niches.
I think we will find this especially true with the (certified) boutique oils marketed to the motorcycle industry by many independent bottlers.
JASO T903:2006 requires the fluid be API SG or later quality. Do we really think an independent bottler is going to first go through the expense of testing his package using API standards, prior to doing the meager testing that JASO requires? Or would it make more sense to buy a pre-formulated package that already carries the API cert, then tweak and test for JASO?