No he wouldnt. Having the greatest physique of all time makes you the GOAT. Hell be the Bill Russell of bodybuilding, not MJ. While Russell was great everyone things, "he had shitty competition". That's assuming Phil gets there. I don't think he will.
There's a difference between that and having the most Sandows. IMO, part of being a GOAT is that this person is also a people's champion, an approachable person with a decent personality. Look, for example at Cedric. He will prob never win the 'O, but what a great person he is.