https://arstechnica.com/information-technology/2019/11/john-legere-t-mobiles-brash-un-carrier-chief-will-leave-in-may-2020/

T-Mobile CEO John Legere will leave the company's top job after his contract runs out on April 30, 2020, T-Mobile announced today. Mike Sievert, T-Mobile's president and chief operating officer, will replace Legere as CEO on May 1.

Legere, who became CEO in September 2012, revived a struggling company and led the "Un-carrier" strategy that pitched T-Mobile as a customer-friendly alternative to the AT&T/Verizon duopoly. T-Mobile's Un-carrier moves changed some of the punitive business practices that mobile carriers routinely inflicted on customers.