It looks like the downstream rebuilders are already working on this and are able to extract (with a bit more work) the information they need from the stream repo. How much Redhat tries to block these approaches remains to be seen, but if they can work around this so quickly then it seems a pretty petty stunt to pull.

https://almalinux.org/blog/impact-of-rhel-changes/

https://rockylinux.org/news/brave-new-world-path-forward/