I believe the PQIA runs as a not for profit, and is not an enforcement arm or any arm of the API itself. Some oil companies do help fund it. We do have to note that the PQIA is here to spot check that oils (and other automotive fluids) on the market are nominally what they claim to be. Their mandate isn't our entertainment, as much as I like reading what they post, and what they do does not absolve the API from policing their licensing nor does it preclude oil companies from watching each other like hawks.
To be totally frank, I don't think PQIA should waste its resources on any product with a legitimate dexos license. GM collects the royalties. GM can test the products for compliance. If they're dexos1 compliant, they're going to be compliant with SN and/or SN+ and GF-5.