Similar situation at Temple in Philadelphia in 2014. They made the announcement in December 2013, and played the 2014 season. Some kids transferred before the season started. I think most ended up at other similar schools (baseball wise).
Yes, unfortunately it sounds like your son will be going through the recruiting grind again if he wants to continue to play. He'll be kind of like a juco transfer, so I would start with schools who like juco kids. Will the current coaching staff be helping them find new homes? Does he have friends playing at other schools who could introduce him to a new school? I would think other schools in the conference might also like to hear from him.
Good luck and keep us posted.