guitarist's mom, Welcome. My son having gone the classical route, I cannot offer program specific advice, but will offer some general suggestions.
I do know that Eastman has a strong classical guitar program, but without knowing your son's performance background, the question becomes can he be competitive at an audition based admissions school not focusing on his genre preference? There is the potential for double majoring at U/Rochester, but I recall there being potential logistics issues. I'm sure details are available in previous threads.
As far as Oberlin, BassDad is the resident expert, and I'll leave comments in his hands.
Your son seems like the Berklee type of person, but I can understand the concerns regarding graduation rates. Additional, I don't know the quality or level of general business courses (if any) available there.
If you haven't already read this post, there is a similar discussion here
Late Bloomer, Contemporary Music - Advice?, and the OP cites a few schools, including Belmont which might bear investigation. Additional,
The New School for Jazz and Contemporary Music and
Contemporary Music Program are probably worth a look.
Another option might be to look at schools with dual major programs, combining both performance and music business degrees if s is interested in the music (as opposed to general) business courses. I know for example Hartt has such a program, but the guitar program again has a classical focus.
Good luck.
Edit: I'm not familiar with U Colorado Denver, but U Colorado Boulder has a pretty strong overall music program... I don't know if you've looked there.
cross posted w/BassDad; added U Colorado line.