My understanding is that page replacement entails replacing the contents of a frame to bring in a new frame in it's place corresponding to a new page. Since it is not the page, but the frame that changes, shouldn't this process be called frame replacement? 
Is the term page replacement actually a misnomer?
terminology;operating systems;virtual memory;paging
Is the term page replacement actually a misnomer?No. A page is the entity in virtual memory.A page frame is the real memory into which it is mapped.So it is the page, not the frame, that is replaced. The metaphor is that the (virtual) page is the picture around which the frame is placed. You move the frame to picture different pages. See here.