It's hard to see given the fluidity of political MOs at the time. By Roman lights, what had happened was a revolt by a client state. If the Roman legions had survived, they would likely have gone after the Cherusci and their allies. The land thus freed could have been used to pay off other tribes and secure their hold, but it is still tenuous. Germany in the first century has very little that Rome's mechanisms of rule can latch onto. I heard it compared to trying to nail jello to the wall once. It is still quite possible that Augustus or a later emperor will just give up in disgust.
If Varus manages to extricate himself, he's not going to be sacked, though. He might even make a career among Augstus' most trusted functionaries. What went wrong wasn't really the betrayal - that was almost expected at some point - but the defeat. Roman troops aren't supposed to *lose*.