I just ordered the T-Mobile Galaxy S5 to unlock and use on AT&T, and am I reading this correct that with this update T-Mobile plugs any exploit that is found on previous firmware just like at&t does? Somebody please correct my assumption because if that's true I'm sending it back the minute I get it and going with the Nexus 5 I know it doesn't have all the bells and whistle but at least its completely unlocked. Don't slap me too hard I'm coming form the S4.
I assume you found this out already but TMOBILE has not locked their bootloader which it seems you think may have happened. It is totally unlocked - no exploit has ever been needed on any of the TMOBILE roms for this phone and I don't think you have anything to worry about. if you already picked up your S5 then you know this - if you waited - come on in = the waters just fine.