T-Mobile's Galaxy S7 and S7 edge are now receiving the November security update
T-Mobile is currently busy rolling out a new software update for both the Samsung Galaxy S7 and the S7 edge. Unfortunately this will not make either device run Android 8.0 Oreo - that update will probably arrive next year. In the meantime, however, you can take advantage of the newest security fixes.
And that's exactly what the new software release for T-Mobile brings. Upon installing the update on your S7 or S7 edge, you'll be on the November 1, 2017 security patch level. As T-Mobile hasn't yet updated its support pages to reflect the availability of this update, there's no official changelog to speak of. Don't expect anything but bug fixes, however.
The new build number for the Galaxy S7 is G930TUVS4BQJ2, and for the S7 edge you get G935TUVS4BQJ2. The identical strings (save for the differing phone model numbers), imply that the exact same goodies are packed in for both phones. The download size is 121.99MB for the S7, and 122.55MB for the S7 edge.
If you haven't yet received the update notification, it might help to manually check for the new software by going to Settings > Software update > Download updates manually. You could get lucky.