What will he have to run for the LetsRun crowd to deem him "legit"? We can speculate all day on what we think he can do, but what would he have to run to validate tri runners and their race splits? 28:30? 28:15? Or would 29:00 satisfy you? Many say his 29:09 at the Olympics was BS because of the "allowed" 5% deviation in course distance, so if he matches 20:09 on the track, would people think he was legit, or would they just say "he should have run that fast because he did it in a tri"?
This is approaching a new horizon in triathlon. We've had Lukas V go from track to tri (albeit with a tri background), but we've never had a true multisport athlete (top tier swimmer/biker/runner) move into the higher echelon of single sport competition.