I disagree it wouldn't help a person who's missed as much time as Mitchell has, and wasn't a finished product before losing time to injury, wouldn't benefit from some time in AAA. In a perfect world AAA is where he should be intil he proves himself major league ready again. We are not in a perfect world so we have to hope he can regain his career trajectory while in the majors.
In truth I think it's as likely Lockridge or ends up taking a step forward and displaces Mitchell or that neither do and we see Churio shift to center as it is to see Mitchell resume where he left off.