If you follow the intel, it seems to be about depth chart and/or starter designation and/or playing time as indicated below. Something doesn't add up though. Season just ended. Kumah finished strong. Off season prep and spring ball is coming up. I can not see Fu or any coach pulling such a senior player aside and saying at that point in time that your playing time is going to diminish. What if Kumah has a huge spring and fall camp. What if other receivers get hurt or booted off the team. Etc. Just no way you tell a guy that your crystal ball says less playing time next year because you are so optimistic about everything else falling into place. No way Fu does that. That would not only be "too honest", it would be absurdly premature.
Now if its Fu explaining the concept that starting positions always have to be earned then that should be obvious. Football 101 from middle school to pros. Kumah can't possibly be offended by that since at best he is a mid level ACC receiver.
So a strange deal here. I think Kumah's ego somehow got in his own way. He certainly isn't going to go to some major program where the same conditions don't apply.
I can not see how Fu could have told him anything to run him off.