It's on the PCI-SIG website, I found the announcement in the newsroom under "PCI-SIG® Highlights PCIe Technology as the Interconnect of Choice for HPC at SC23"
https://pcisig.com/sites/default/files/newsroom_attachments/...
> PCI-SIG announced the new naming scheme for PCIe Internal and External Cables will be CopprLink™ . The PCIe 5.0 and PCIe 6.0 Internal and External Cable Specifications are currently in development and are targeted for release in 2024.