The Surface Duo spotted in the wild appears to be a pre-production sample that is tested by Microsoft employees. Unlike the model showcased last October, this one comes with a LED flash on the front and appears to be slightly slimmer, as well. Unfortunately, this could mean that there will be no rear cameras.
https://www.notebookcheck.net/Wild-Microsoft-Surface-Duo-appears-on-a-Vancouver-SkyTrain-passenger.453184.0.html