Choosing not to support said interfaces would be the biggest breakage of userspace in 3 decades of Linux history. Such a course of action is nowhere specified by the people who would be responsible. As best I can see you have constructed it from whole cloth from suppositions that seem to be ill considered.
Edit: To be clear breaking user space is when a change happens in the kernel level wherein software that used to work no longer works because the public interface presented differs. If you have evidence that this is actually going to happen other than your own misunderstandings please link it.
Edit: To be clear breaking user space is when a change happens in the kernel level wherein software that used to work no longer works because the public interface presented differs. If you have evidence that this is actually going to happen other than your own misunderstandings please link it.