Apple DOES say that, when you set up FaceTime and iMessage!
There is a pop up that says "Your carrier may charge for the messages used to activate iMessage and Facetime" You can choose to not activate and do it later.
There is a pop up that says "Your carrier may charge for the messages used to activate iMessage and Facetime" You can choose to not activate and do it later.
There’s a field in there that configured whether that warning should be shown.
My memory, which may be wrong, is telling me that the first major version of iOS which included iMessage did not include the warning at all, and that it was added for non-whitelisted carriers (aka those which did not sell the iPhone) to prepare the user for the possibility that they will be billed, based on user feedback precisely like the comment to which I was replying.