No they won't. If a 4680 battery has, as Elon stated, 16% less mass than the 2170, that would reduce the Model Y weight some 170 lbs. If Tesla reduces the number of 4680s to equal the 2170 pack's range, the car is going to weigh some 300 lbs. less. So, the, "Refreshed M YLR" will HAVE to have different specs. (Unless they add a bunch of lead to the car to equal the current specs).
If they DO keep the weight the same with the 4680's, my vote is that they do as others has suggested: software-reduce the range and, "unlock" it later for more money. We will know soon with the new Certificate of Conformity.