I don't know what you mean by this, but I assume you are asking if the PvE element disappears. It shouldn't, but who knows. I think the environment will continue to a threat from what has been said.
Not only that. Yet it seems that a diplomatic victory in its usual form is too light and kills a play. Now, if after a diplomatic victory would prove the right of union to life in a super complex PvE, it would be much happier.
Or as in "Fall from Heaven II" just to make counter Armageddon, or something like that, that would be the end game independent monsters are all yet had their weight and PvE was important.