Proprietary technology meant technology vendor technology bought and used by T-Mobile, not that it was proprietary to T-Mobile, unless Legere believes that T-Mo

Proprietary technology meant technology vendor technology bought and used by T-Mobile, not that it was proprietary to T-Mobile, unless Legere believes that T-Mobile's specific call flows or specific snowflake network configuration is part of this definition. So other carriers sure could implement the same thing, but nobody is crazy enough to do that until they figure out how T-Mobile subscribers and the FCC respond.