Red Hat and AdoptOpenJDK will be supporting OpenJDK 8 for quite some time yet. Oracle's JDK and JRE will stop getting public support, yes, but OpenJDK 8 will be alive and well for many years to come.
I was not referring to that. I was referring to the matter that they weren't ready to jump TO JDK 8 when JDK 7 was EOL, nor the next year, nor the next year after that.
What did they do with security updates when they were available for the version they were on?
Questions.
Don't get me wrong, they're not the only ones ice skating uphill on this.