It does take some time for a device to come up with root access but with a popular smartphone like Samsung Galaxy, Motorola Moto phones and HTC phones. Did you ever come across root before they actually hit the shelves? Chainfire has come up with root tinker out of box and that should make your day atleast for sometime.
Auto the CF-Auto Root Repository confirms the root availability for these two T-Mobile phones by Samsung running on Android 5.0.2 Lollipop out of box.
The release note highlights that root might cause problems to KNOX security, hindering the mobile payments. If you are ok with that, you can proceed with root.