How can I hide some UI elements until the mobile version is out?

The first picture depicts a design of notification preferences that is really strongly inspired by Backplane's solution (the second picture), because it suits my case perfectly.

The client saw the original design and said that they want to include the Mobile Push notifications as well, despite there's no mobile version yet. They said they want to grey it out, so it does not bother the user, but it's still there, already implemented, ready to be used in the future. They say it's easier to put it there now, then to remake it once the mobile version exists. I was trying to explain that it makes it unnecessarily cluttered to include something that will not be used for a long while, but they kind of insisted. However the discussion has not ended yet I think, so I started to think about how to accommodate both ways.

• I started with taking the mobile notifications and putting them on the side, instead of in the middle (it's already within the design).
• Next I was thinking about hiding them altogether (not yet within the design), giving them the color of the background for example, so they're not "there" for the user to care about (my way), but it's still there, considering the code (client's way).

I know it's pretty weak, but it's a first thing that came to mind that goes along both lines of thinking.

Any thoughts as to why it's a bad idea? Or any other concepts to what I could do here?