SGH-I337 Lollipop OTA Update topic

Hi all. Kinda new to all this. Just picked up a I337 and had the former owner get it factory unlocked. Phone is still unrootes. So right now I'm using it with T-Mobile on a prepay plan (work phone is unlimited everything so its my daily drive but its an iPhone). My question is since the SG5 L update was just release I figured the S4 update won't be far behind. Do I need to be on ATT's network to get the OTA update?

Sent from my SAMSUNG-SGH-I337 using Tapatalk