Like any other vendor of "a commercial-training product in support of their commercial operating system," it should come as no surprise that its product
(that is to say, "a certificate") will always be tied [only ...] to the most-recent version of their operating-system product.
You might be able to contract for
training pertinent to "earlier versions," if you represent a big-enough group to be of any commercial interest to a training provider, but you probably would not be able to get a certificate for that version anymore.
However, if you will for a brief moment allow me to indulge a brief consideration of
"the journey," as opposed to
"the reward," I would point out that ... in the real world ... you can't necessarily predict what Red Hat version(s!!) a particular "shop/employer" might be using. Therefore, it
never hurts to make it your business to be very aware of how the OS has changed from one version to the next. Even though
Red Hat, corporately speaking, might quite-naturally push "only its latest thing,"
you, on the job, must be "a Jack/Jane of All Trades!"
