theres no way in hell rex is shooting ashoka , u can see why on season 4 rex disobeys orders from that jedi ,he can disobey orders rom the emperor, and many clones defected during order 66 why cant he ?
and i think that the show is giving us clues to what will happen, rex meets a defector, he question orders , he values experience over rank. alll these things indicate rex is not going to shoot ashoka.
i have a feeling that george might jsut leave us hanging and not give us an ending to clone wars.