Singtel. But i really don't think it has anything to do with the telco.
Perhaps you can try manually updating your TVs firmware through Samsung's website via a flashdrive. I always update the latest TV firmware this way.
Last update for my TV was on 18th Dec 2015. And Netflix just automatically installed on my TV yesterday
Haha, my Samsung Smart TV just spoilt last week, now using Sony, non-smart non-Android.
Just my guess, Singtel/Starhub/M1 users, the backend of the various brands (Samsung in your case) "sees" your region as SG, so push down the app to your set.
MR/VQ users, due to their value-added service (Teleport/FreedomVPN), the backend of the brands "sees" the region as "US", so there is no need to push down the app. In this case, I am not sure changing the WAN DNS value to 8.8.8.8, 8.8.4.4 will help or not.
Just my guess.