Aquadalte,
My input was from an A320 point of view where in normal law in case of overspeed: (from A320 FCOM)
As the speed increases above VMO/MMO, the sidestick nose-down authority is progressively reduced, and a permanent nose-up order is applied to aid recovery to normal flight conditions
.
So even though you are getting into the low speed regime, the aircraft thinks you are in an overspeed and normal law will not allow you to lower the nose.
If I understand you right you suggest the only initial way to get out of this is to dumb the aircraft down to ALT law. Which I would agree with.