intel is not in the business of giving away free silicone, even you have to pay to unlock the feature because there's a chance intel is going make a loss, i dont think that sit well with intel
a more reasonable explanation is that these chip sit in between bins, either marginally passing or failing a bin, so on the safe side intel binned them into a lower tier, then after some extensive testing found these chips to be more resilient and decided to charge to unlock them into the higher tier bin, could well be the reason why OEM chips are only affected, because they get their shipments well ahead of retail
intel has probably already written off the cost of these chips, why not just give out the unlocks as a gesture of goodwill, but then that would really be against their nature