As of last fall, Google has started publishing monthly security updates for AOSP devices (that's the Nexus lineup along with the Pixel C). They have also made these patches available to their partners (Samsung, HTC, LG, Motorola, etc) to roll out to their devices and have uploaded the patches to AOSP for everyone to use. Typically the carrier-branded smartphones and tablets don't see these updates, and if they do, they are months and months behind - this is mostly due to the number of certification tests that need to be done. Although lately, we've seen Samsung pushing out updates to some models pretty quickly. And that includes the Galaxy S7 and Galaxy S7 Edge on T-Mobile. Which are getting the May 2016 security update as we speak. This update was just announced by Google earlier this week.
The security update from Google is a pretty big one and patches quite a few exploits found in Android, although some are only affecting Android One and Nexus branded devices. This update also turns on the dormant FM radio that is included in the Galaxy S7 and Galaxy S7 Edge. For those that might be wondering, the build numbers are G930TUVU2APD7 for the Galaxy S7 and G935TUVU2APD7 for the Galaxy S7 Edge. What's interesting about the FM radio is the fact that while it's being turned on, there is no FM radio app pre-installed on the Galaxy S7 or Galaxy S7 Edge. But that's an easy fix, as there are a number of apps available in the Google Play Store that can play FM radio without using data.
T-Mobile's changelog also includes some device stability improvements and bug fixes. It's worth pointing out that this update was actually already announced, and was slated to fix the volume buttons. However when it was announced, that is all that was made known about the OTA. It's nice to see that this update is a bit more than just the volume button bug fix, especially nice to see that it includes the May 2016 security update. We don't see those all that often on devices that aren't Nexus, or AOSP devices like the Pixel C.
If you own the T-Mobile variant Galaxy S7 or Galaxy S7 Edge, you can head on into Settings > About Phone > System Updates and tap on "Check for Updates" and you should be able to pull down the OTA. It weighs in at about 164.61MB.