Apple won't find itself standing alone. Other major distributors like Google and Valve are both happy to take 30% off the top of app sales too, and if the chance comes to speak up in support, they will. But the difference is both of them can be circumvented by competitors, for instance Epic Games, who is challenging both. (Epic is launching an Android store soon.) Apple can't be, and that's likely to be the crux of any action against them.