you’re right
you’d read something about RH’s philosphy… 
during all the lifetime of a release (say 6.X) there won’t be any release (major) change in all daemons/sw coming from mainstream…
I mena… if you install centos 6.0, you’ll find mysql 5.X.Y… it won’t never be changed to 6.W.Z or 5.T.K.
more info here:
https://access.redhat.com/support/policy/updates/errata