This is, in all fairness, a wild oversmplification.
If you believe that everyone would be happy, you don’t know this community.
That didn’t go off without a hitch, either. And the AH had already gone through more than one modernization step which Classic has not yet undertaken. To assume they could leap all the way to Retail’s current state in the midst of an under-availability crisis is… unreasonable.
We have no idea what that would entail software-wise.