Jeremy Horne had a great career at UMass, and was on the KC Cheifs roster last year. Gilbeaux had a good career at U. Delaware and made the Tampa Bay roster. Kareem Jones and Reggie McCoy had decent careers at Delaware State. Other SU-1AA transfers include Michael Kay (Norfolk State) and David Legree (Hampton), who was wived by the Colts this summer.
I don't know the backstory behind Jones' departure, but I'd imagine that SU's engineering program (like Newhouse) is extremely competitive, and Jones may simply not have had the credentials to get in.