The cover of Sports Illustrated is a notable achievement for the subject and photographer alike. For the November addition, photographer Michael Lebrecht used the Motorola Moto Z with the Hassleblad True Zoom Moto Mod attachment to photograph Dwayne Johnson. Quite an achievement for an Android phone too, with the attachment only really providing an optical zoom.
It has been done before, although not for Sports Illustrated as far as I know. As far back as 2012, also near the time of a US election, an iPhone shot of hurricane Sandy appeared on the cover of Time magazine. Publicity stunts by the magazines? It certainly seems that Sports Illustrated requested the use of a smart phone specifically, whereas Ben Lowy who photographed the Time cover was already well know for his phone photography.