Such isn't the case for Samsung Galaxy Note 10.1 2014 and Tab 4 owners on T-Mobile. Both of these devices are only now getting an update to Android 5.0. Not 5.1.
On the Note 10.1 2014, look for firmware version P607TUVUBOI2 in Settings following the update. On the Tab 4, you will run T337TUVU1COH5.
Sure, 5.0 is better than KitKat, and most users won't notice a difference. These updates also contain the Stagefright fix. But come on, Samsung. Let's not make this a habit.