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.
If unlocking is made mandatory, the phone subsidies will end. People will be forced to pay full price up front, or else effectively pay more as interest (even if that interest is effectively "hidden" in the overall increased price). So yes, this regulation is exactly about that.
You are wrong, empirically. We tossed that bollocks out in Canada seven years ago.
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.
Sure, but how does the company account for the losses from people who get the phone and then stop paying and switch to another carrier?
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.
Or they buy the phone with a credit contract, as happens in the rest of the world.
If the major telcos only offer exorbitant interest rates, some other player will step in and offer the credit at better rates that fairly price the risk.
The interest rate on a credit contract will depend on the default rate. Arguably, a phone company can offer loans on a locked phone for lower interest rates than anyone else could, because they can cut off service if the loan isn't paid, which is an incentive to actually pay it.
I'm not all sure this is a good thing, but I can see the argument for why it might result in lower interest rates on phones.
None of this is going to matter to people with good credit.
...alternatively, the cell companies will just sell unlocked phones with the subsidies, since you're still locked into the same 1-or-2-year contract that was paying for the locked phones. This won't stop them from making those precious fractions of a cent from bundled shitware. They'll still make their money.