I do not favor high school distance runners going pro. They have not been medal contenders, unlike some sprinters. 3:34.36 is fantastic for a high schooler or a collegiate. But collegiates in the summer have run 3:30-31 and medaled, and Nuguse just ran 3:34.68 solo. Tanner ran 3:34 as well. A college aligns you with thousands of fans, provides a team, an education, room and board, and coaching/facilities worth one hundred thousand to four hundred thousand dollars. It gives you competition in three seasons, including the xc season that is invaluable. For pros, it can be difficult to find races nearby sometimes.
But Kessler would still raise his value, now that many are paying attention, by smashing Alan Webb's mile record on national television. A sub-3:50 would also get attention. I did not see even the category of running or the story on espn even under "Olympic Sports." The best schools for milers are El Doret, the Very Nice Track Club, Oregon, and Washington. NAU would orient him in the 5000m direction.
I suspect he'll be a very good championship racer in the future, given his great speed at the end of workouts already.