Just had a look at the video - hard to work out from that what shape Gatlin is in. He does look as lean, fit and as smooth as he did at his best.
Which reminded me - had a quick look at Justin Gatlin circa 2004/2005 on a few Youtube videos. The bloke was a super runner in his day, practically unbeatable for a while, smashing most fields much like Bolt does now. How soon we forget!
I doubt he’ll match Bolt and maybe Gay but if he can get back to his best, he could certainly challenge for a place on the podium at one of the Diamond League meets.