I would think that this would be the case. In any one transmission there will be a systematic error due to the fundamentals of the transmitter / receiver. Is there also a transient or stochastic error from any given transmission that could be effectively eliminated by multiple transmissions of the same data?
Any sources on this would be appreciated.
A somewhat related question: If an orbiter is receiving data from a probe or lander, would it use the primary communication antenna for that, or would it use a different one to keep the primary pointed at Earth?