I'm impressed about this clever wording....
The Term “Numbers Matching” used in our descriptions refers to an engine that has an: engine block casting number and date, engine assembly date and suffix code, and engine VIN/serial number that are present in a manner that is consistent with build sequence of the described vehicle.
IMO, today's buyers may not be as demanding in having an original stamped part so a restamped one will be acceptable even if they are told out right. After all, if you are driving it around, an original or restamped doesn't matter......each will give you just as much fun.
Whether we like it or not, those restamps are here to stay even if it is kept a secret as to what to watch out for.