Ever Quest has been out for 18 years and is still going strong. Their latest expansion is the 23rd in the series, and was released November 16, 2016.
Even if this game has a very niche playerbase, they continue to make content and release expansions for it.
Given this, what makes ANYONE think that WoW would EVER end?
WoW will continue to be expanded on for years and years to come. There is so much lore and so many things they can do to create new and refreshing content that im just surprised that anyone could actually believe that the game is dying or would end in the forseeable future.