Therefore, its known narrative elements are not a part of the Doctor Who universe as we, on this Wiki, choose to define it. It may have been the basis for a similar story in another medium, however — and that story may indeed be valid.
Deceptions was the planned Eighth Doctor Radio Times comic story to follow on from Perceptions. Writer Gary Russell's planned the storyline involving the shape shifters from the previous story to be revealed to be the Zygons. This was derailed by the cancellation of the comic feature in Radio Times, therefore, he had to wrap up the plot quickly, in an abrupt and perfunctory manner, and Coda was written to wrap the story up quickly. (DWM: 272)