The T-Mobile Galaxy S6 leak wasn't Android 5.1. Instead, it was Google's latest update Android 5.1.1, a piece of software that's still rolling out to Nexus users.
Rogers says that its Galaxy S6 and Galaxy S6 Edge updates will be based on Android 5.1 though that could certainly change in the weeks leading up the release.
At this point, we'd count on Android 5.1.1 for most people. And if Rogers or anyone else goes with Android 5,1, we'd expect Android 5.1.1 fixes to be baked in. Android 5.1.1 comes with some crucial fixes and we can't see Samsung opting to leave them out.
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