You got it wrong
Apple (and every other manufacturer) can already carrier lock a phone.
But carriers are the ones that actually carrier lock phones, not manufacturers. You're also seeing the problem backwards: the real issue is that you can't swap out your SIM and use a different device if you want/need to. And a soft SIM will be locked permanently as well, so it's just going back to the dark ages of CDMA which I won't ever go back. The SIM card is an issue of consumer freedom and should not be allowed to be turned into yet another lockdown method.
As it is, phones can be SIM unlocked in most civilized countries for free, for a fee, or by some h4xx0r dude.