> so it's almost certain that private APIs would get accessed

No it's not. Just like with ObjC or Swift, in ASM you have to be explicit about the APIs you want to call. I don't see how you would accidentally call a private API in ASM.

IMO the bigger risk is attempting to call a method that does not actually exist. ObjC or Swift would protect you from that, but ASM would not and may just crash at runtime.