If they just want a free (beer) RHEL clone, the best choice might turn out to be ... Oracle Linux. Who would have thought?
Is CentOS the upstream for Oracle Linux? Instead of which comes CentOS Stream and then the question is what will Oracle do? Would they even try to keep the old CentOS concept alive?
EDIT: This may be inaccurate; see https://news.ycombinator.com/item?id=25348496
My familiarity with Amazon Linux is about 4 years out-of-date these days, but it was a RHEL/CentOS clone with a number of the core libraries like glibc being updated and maintained by Amazon on an independent life cycle.