Hmm interesting, I was linked to an OCP dropbox with a version that did have the connector pinouts. Maybe something someone shouldn’t have posted then…
I could find OCP accelerator spec but it looks like an open source reimplementation, not actual SXM2. That said, the photos of SXM2-PCIe adapters I could find look almost entirely passive, so I don't think all hopes are lost either.
couldn't someone just buy one of those chinese sxm2 to pcie adapter boards and test continuity to get the pinouts? I have one that could take like 10 minutes