If SSD manufacturers decided to stop producing 256Gb modules, and start with 512Gb, would Apple be pissed?
No, it would not piss off Apple. In fact it might please them. They'd just work out a way to disable half the capacity. And make it so that if hackers tried to open up the extra capacity, the mac would be permanently bricked.
Apple low memory and disk units would be below Apples cost including its "normal" "Apple" profit. Apple offers them with the expectation that people will upgrade to a workable disk size and Ram size. Apple presumes few will buy them, and if they do, Apple sales of them would be viewed as a loss and would write those losses off as marketing expenditures.