Even if it's possible, for Apple, it would be an utterly disastrous thing to do. Imagine the damage to its reputation. If they were to do it in this situation, the argument would go, what about other situations? What about all the phones they sell in China, for example. Are there circumstances where they should brick all US Democrat or Republican phones? It would be the end of Apple, and that's why it would (hopefully, thankfully) never happen.
Parent wasn’t making a slippery slope argument FWIW. They were making a PR argument based on the propensity of the general public to fall for slippery slope arguments.
