“Nothing’s too personal for me,” says Jason Isbell. And indeed, during a discussion about Reunions, his new album with his band the 400 Unit, out today, and his career, he never avoids answering any question- except one.As fans of his previous six albums are aware, the four-time Grammy winner is a singular story teller who often reveals more truths in a few words than those less adept do in a whole album.