The Concept of Ending A Series Before It Was Supposed to End
Imagine if James Gandolfini had died before the production of Seasons 6A and 6B of The Sopranos commenced production.
Imagine if -- for whatever other reasons -- Bryan Cranston couldn't do the final season of Breaking Bad, or Jon Hamm couldn't do the final Seasons 6A and 6B (or was it 5?) of Mad Men?
Well...I guess we would have lived with the endings of the season before that happened.
It would have been fine in either case.
I'm guessing that's what happens to House of Cards. It ended well enough last season to be considered...ended.