I'm with you one this, I don't even know if Apple would approve apps using NS prefix without their consent.
I used the word "inspect" carefully. Apple is probably looking for calls to private APIs by looking at the addresses of functions called in your binary with the addresses of private APIs.
They are probably looking for method swizzling of Cocoa APIs by looking at the address passed into method_exchangeImplementations, class_replaceMethod, etc.
Looking at the symbols within a binary is probably more effort than it is worth and probably isn't going to be very effective.