In some areas T-Mobile has access to more band 71 spectrum than Sprint had B25...and B71 goes further than B26...and it's the band where T-Mobile's nationwide 5G is deployed (usually all but 5 MHz of band 71 is used for 5G). Without B71, low-band with TMo is *at best* 5 MHz of B12 LTE, and some areas don't even have that because other carriers own all the B12 licenses.