Ultimately, all such a status page would say was, "Upgrade as soon as
you can; don't start new projects on old versions". Rails isn't like a
Linux distribution, where there are multiple supported versions.
Occasionally a really severe security bug hits and the patch is ported
to previous versions, but that's only happened once or twice in
several years. Otherwise, development and support is focused on the
current version. If you show up and report a bug in 2.2.2, the first
question is likely to be "have you tried upgrading?".
--Matt Jones