Instant Tea called it transphobic, but some commenters disagreed. Either way, the ad has been pulled. From All Things Digital:

By mid-afternoon on Tuesday, the groups backing the ad had begun receiving complaints and a Sprint representative confirmed to Mobilized that the ads are being pulled.

“We believe the proposed transaction is really bad for consumers, the industry and the country,” a Sprint representative said. “We supported these efforts to get that message out broadly to consumers. We certainly apologize the material offended anyone. That was not our intent.”