It’s for the best, really. Since Rudy Giuliani appears to be running America’s foreign policy unofficially anyway, it’d be nice to elevate him and give him the title that befits his position.
Granted, granted, the Senate would never confirm him, but that’s no problem in 2019. Trump can do some of that jujitsu he performed to install Ken Cuccinelli as acting head of USCIS even though a new appointee wasn’t supposed to be eligible for that position. In order to satisfy the requirement that an acting secretary must already be employed by the department, Trump could just name Rudy the new janitor or whatever at State before elevating him to fill Pompeo’s vacancy.
It’s not like the Senate’s going to assert its constitutional prerogatives by objecting or anything.