How long till I have to pay Apple 30% for ordering a pizza using an iPhone? How long till I have 30% premium to pay for shopping online using a mac computer?
That 30% will not come out of your pocket; it will come out of the provider's pocket. Apple will see to that, don't worry.
Apple will amend that agreement as many times as they need to in order to maximize the benefit to them. Let's not kid ourselves and think the benefit is for their users. I think we're all wise to that one by now.
What's likely is that either the users will pay and know that they are paying extra, or the users will pay and not know that they are paying extra. The second case already happens with credit card processing fees, and the costs incurred by credit card users are usually spread across all users.
Of course, the providers could decide to just make less profit from now on, but that seems fairly unlikely to me.