He signed up as an enlisted man. why would he become an officer? ONly the German aristocracy become officers, and even in Britain it worked on a similar process. It's only these days that officer ranks are chosen largely on merit and not status.
I agree with the general consensus here that if the still obscure corporal were killed in combat, Germany would still have become a dictatorship after the Great Depression began. Before 1933 the KDP and NSDAP were fighting in the streets. It wasn't clear who would win but it could be argued that the military establishment would not have allowed a communist dictatorship. The the political right was apparently weak (without the NSDAP) so I think it would have been a military dictatorship. I love the name Blumentritt but I'm not saying he'd be the leader.