Sure, heading off to Ethiopia and training with some decent runners hasn't been terrible for Mo, but running 2:05/2:06 isn't going to cut it if he wants to challenge Kipchoge in Tokyo or even medal. He should go back to Salazar and train with Rupp if he wants to really step it up. It was under that setup that he was the best in the world, and having the best coaching, best training partners, best recovery resources (cryotherapy, etc.), and best strength training will be what it takes to bridge the gap to Kipchoge. Sure, he may very well still not be able to challenge Kipchoge, but he certainly won't do it if things stay the same.