My thoughts? EEK! I think this is a recipe for trouble. I hope this was not suggested by the contractor?
These floors need smooth surfaces underneath, with underlayment that will support the flooring. If there will be serious problems like that, they need to be fixed before you put down flooring. Otherwise, you will have flooring that flexes every time you walk over a spot. You will have loud squeeks. The joints between the pieces will open up and close, allowing dirt to lodge in there, unsightly lines will appear in the flooring. With enough flexing, the hard surface coating on that flooring will start to crack.
While padding is used underneath these floating floors, the flooring is simply not stiff and strong enough to resist the flexing I am talking about.
Do the job right the first time. You don't want to tear it out and redo it later. If the cost of repairing the subfloor is too much, just replace the carpet.