my understanding is:
if you have a "F.N."clause in your lease, you can sign up now & if the prices goes up in the furure you will be compensated at the new higher price.
No company is going to "grant" a favored nations clause. That would be the same as you buying a car from Wray Ford for $20k and the contract states if the dealer sells the same car in two months for $18,500, then they will mail you a check for the difference.
CHK gave my family a FN clause. It is true that CHK grants them. So hopefully the people with land next to ours will actually end up helping us out. But, yes it is a fact that CHK will grant a FN clause.