Does "Synchronous-Commit Availability Mode" ensure consistency between Replicas?
SYNCHRONIZED state only ensures that the writes are hardened by the secondary (log written to disk). It says nothing about them being applied (data changed). 


  can I expect consistent results to be returned from both replicas, every time?


Yes. The reads are consistent, always. But keep in mind that in relational parlance consistency (ACID) has a different meaning from the distributed (CAP) consistency. You are not guaranteed to read the most recent consistent state. Particularly, you are not guaranteed to read your own committed writes. And the reads from each replica, while each being consistent, may not match.