Kyl will not have served in McCain’s seat for a whole four months when he departs at the end of the month.
I think the reason McSally didn’t make an ass of herself during the prolonged ballot counting in her race has been pretty much confirmed.

Jon Kyl to resign from Senate, leaving GOP governor to fill McCain’s seat again https://t.co/TmYHVg3GJm pic.twitter.com/KKsbE3dsCm

— The Hill (@thehill) December 15, 2018