Based on Stokes making a huge deal about leaving after a year and a half of play. He put in the hard work over the summer in hopes of getting drafted this year. I'd say the $500,000+ paycheck is enough to itch Stokes out of the undergrad program. If he wants to finish his degree, there's a program for students who go professional to finish up their degree while pursuing sports. I remember there was an article in the Tennessee Basketball magazine about Tobias doing something similar.
Of course this is all speculative, but what would make Stokes want to stay and finish up a "Communication Studies" degree and risk a year of getting hurt and losing a hefty paycheck? If Jarnell can get in the high 2nd round or 1st round he's gone.
If his degree had significant value, I could see him staying and finishing up. Also realize that Stokes is still a sophomore (and a half) when it comes to classes. So unless he's done extra school work in the summer, he still has 5 semesters left of class hours (including this fall/spring).