Grant showed that even one of the all-time great USA runners can't hold a peak all damn year. GST, which I was never a fan of, really had many of these runners running waaaaay too early in the meet in the year, particularly when Worlds was so much later in the year. Perhaps they, and their coaches, thought that they could mini-peak, win some $$, go back to training, and then run well in September. Turns out that most of the runners were just tired and a little off where they should have. Even Arop, getting a medal, looked more tired than usual.
Grant is fine and not even close to done with his career. But I do think that trying a marathon would be an interesting move for him before he hits his 30's.