Notice Alma's explicit mention:
"In the immediate term, our plan is to pull from CentOS Stream updates and Oracle Linux updates to ensure security patches continue to be released."
They did something similar with the Kernel in 2011. They stopped publishing the git tree for the RHEL kernel and only published the tarball with no version control. At the time, Oracle started a project to reverse engineer it back into a set of unique patchsets. Was kindof wild.
Not sure how long it lasted. It doesn't seem live now, though.
https://www.theregister.com/2011/03/04/red_hat_twarts_oracle...
https://www.theregister.com/2012/11/12/oracle_launches_redpa...
Paying enterprises that decide to go with Oracle Linux are the real threat to RHEL not the free alternatives.
Very few people that are on the free alternatives will start paying for RHEL if the alternatives go away, it is more likely that they move to another distribution.
This is not even the first time Red Hat try to make Oracle life difficult.