Everything will get removed. At some point OpenGL will get removed, at some point (much later) Metal will get removed, at some point (much later) OS X will no longer be around.
This is not like 32 bit being announced that it is being removed. Announcing being deprecated (as opposed to the state that it has been in) is not announcing its impending removal - that is in the foreseeable "soon" future" that would have any meaning.
People are under the impression that Apple is signifying OpenGL will be removed in the soon future of a couple years like 32-bit, and I am saying it does not. Although it can have the interpretation of the first step in doing so, like I said, it would be too devastating and so am not worried that Apple will remove in the soon future that has meaning (which I think at minimum if everything went right and the vast majority of software changed and no longer used OpenGL for at least 4 years, would be at least be 8 years away if ever).