Not anytime soon. What phone do you have? N4? It's anyone's guess. But with a educated guess, I would have to say It may not hit the the previous models. I'm using the beta and there is still much work to be done and more bank institutions that need to join. It would be nice if it was just an app install from the store like Google Wallet, but I don't think it will happen anytime soon. The N920I versions don't even have Samsung Pay.
Why would he have a nexus 4 in the gs6 active forums? He has a gs6 active.
I'm also waiting for Samsung pay to go live for our phones. Other than the fingerprint reader, the phone has all the other technology- The mag stripe sensor and of course, NFC.