Here is what I have done with my AT&T Priv.
1. Download both AT&T and common non-US carrier autoloader archives from BB website and extract them to separate folders. Make sure to download the closest versions of the two autoloaders.
2. Replace img/oem.img file in AT&T autoloader with the one from common autoloader.
Run flashall script in AT&T autoloader to flash your phone as usual, you will be upgraded to the latest AT&T ROM without those AT&T bloatware.
Bonus:
If you would like to preserve data when flashing autoloaders, i.e. upgrade without reset your phone to factory default, follow this:
Open flashall script and comment out two lines that run below commands:
fastboot.exe oem securewipe
flash userdata %IMG%\userdata.img
Then run flashall script as usual.
Above are all tested on my phone without problem.