This has been mentioned on here before, but I just checked my owners manual, and there is no mention of it.
I think it is good advice, as the different diameter will make the rear Limited Slip Diff work overtime, and could cause longer term problems if left on for too many miles.
But I do not think that it would affect the TOD any more than putting it on the front.
Of course, that is a free opinion, and we all know what they are worth.
PK