because the prophecy becomes fulfilled on skyrim area :the staff breaks daggerfall:nimiduin rises morrowwind:mountainous fire oblivion:the gates of oblivion open skyrim: a civil war ensues and alduin is unleashed therefore completeing the series
The elder scrols is but one prophecy in tamriel there are many more they can take from lore or add to lore. besides how do you know the prophecy ends? thats jsut where they knwo it will. maybe there is mroe to it then they know mayeb theya re missing a scroll.