He didn't say why they wanted him to come back..but he did say the last few episodes. So my guess is that they were going to have her be torn between Dean and Logan. In those last episodes where she's back in Stars Hollow my friend and I were SO upset (b/c we were watching this after we knew they wanted him to come back) b/c we were like, "DEAN'S SUPPOSED TO BE THERE! I BET SHE WOULD'VE RUN INTO DEAN IN THE CORN MAZE!" and so-forth! haha I agree..it definitely makes me even less satisfied with the ending to know that they weren't finished with Dean!