This is not about an individual sharing the source. This is about near verbatim copy distributions like Oracle Linux. And they can easily see who contributes code from RHEL into those distributions.
I think Jeff has a point that a Linux distribution is a collective effort, but I honestly don’t see why he can’t just target Fedora which is for all intends and purposes the testing release for RHEL and most of the development work that Red Hat does goes directly into Fedora. RHEL adds little of value to that other than some compliance BS for large companies.