The potential regulation is about the government making phones unlock automatically after two months of purchase. The regulation isn't about banning discounts or sales.
Miraculously, carriers simply started offering "tabs" or other language where you pay the subsidized phone cost as an addition to your plan bill for the contract period, with a clause that if you cancel early you still have to pay up the difference.
Arguments in favour of locking are nothing but corporate apologia and business crying wolf.
What happens is the overall price goes up to offset those losses, even when it's not explicitly labeled as such. That's just basic economics. Empirically.