So far it is just especulative stuff, but IMO this could derive from a somewhat flawed Thrust control system in the A320
You are quite right: How can any aircraft allow an engine to be put at high forward thrust while the other engine is in reverse, and with all this happening in a normal landing and touchdown ?
So we seem to have a classic man vs machine problem here. Who should win? the man or the machine?
So maybe you are saying that the machine should be given even more power in case the the man forgets to do something and ends up in violation of the rules of the interaction?
But then we have the other situation, where an engine fails catastrophically at Vr and sends an incorrect signal to the machine that the reverser has been selected, thus causing the remaining good engine to go to idle. OK, so my imagination is a little off. But the issue is who is in charge, the man or the machine saying "retard"?