I wouldn't be disappointed if he did, DB appears to be handling things as capably as ever so i don't think Cav would suffer from a move.
Hats off to him for showing enough modesty to be a bottle carrier during the TdF this year, that really was great to see, but wouldn't it make Sky an even more effective team chasing GC on Grand Tours if they had another two strong all-rounders rather than a sprinter and his helper?
Might be a better way to seek to consolidate this years TdF if you had 3 or 4 guys with a chance of holding a decent place on GC, especially if they were credible stage winners - if you had Bradders/Froome placed on GC you could send EBH or G up the road for the stage win, and/or time on GC, and still have enough strength to maintain main GC.
Note to self, stop saying GC.