I can't tell you specifically for RKE2, but I can point you to https://kubernetes.io/releases/ for Kubernetes release EOL info and mention that when I asked one of the Rancher folks if 1.21 would end up as an officially supported RKE2 version rather than a tech preview the response was that 1.21 only had a couple more weeks until EOL so no plans.
So from there I think you can expect potentially similar EOLs, though since RKE2 bundles CNI & Nginx ingress controller you might see releases after EOL to update those if something critical hits, though I have no idea for how long.
09/21/2022, 11:26 AM
09/21/2022, 4:42 PM
Yes, our releases have the same support cycle as upstream Kubernetes. When Kubernetes minor versions go EOL, ours do too.