RHEL saying '8' or '9' is supported for 10 years is misleading af. Each 'minor version' (which are, in fact, sometimes large changes!) is supported for it's own specific time period. Odd numbered (8.5, 8.7) for example are only supported for 6 months.
https://access.redhat.com/sites/default/files/images/337_rhe...
It's terrifying actually.