It will depend on talking with teams rather than mock drafts, but using the assumption his stock is high, there are a couple of reasons the above doesn't work.
1) He's not good enough, alone, to make a mid-major do much, that wouldn't have done much without him.
2) If he plays college he loses a year of income..
I just don't see it.
Why does he lose a year of income? He joins in December and leaves in April. He can't play in Europe for that duration as a 18 year old. In the Australian league he could join for really small bucks but worse coaching and individual development. DLeague could be a possibility as well but uniform D-League joke contracts $40k/season are making it hard to decide to that route.
So why not join a strong individual development coach whose program you propel a little bit or practice with a good program.
I don't know if individual trainer like Grover give loans/back loaded payment plans or if his parents have the funds to let him practice individually for half a year leading up to the draft.
I just think with more tape for the scouts he might solidify his high position.