For quite some time I've felt the biggest flaw with wows storytelling is how much goes on simultaneously without direct explanation by the authors. While it doesn't necessarily hinder your capability to comprehend the progression of the story, it definitely doesn't come off as transparent as the reign of chaos campaign set the buildup for faction conflict in wow, or how tft showed Illidan and arthas' intertwining story arcs.
So as the title says, even if you have no real itch to do more than one playthrough the rts campaign, would you be for a warcraft 4, or is the somewhat detached narrative that we experience in wow clear enough for the playerbase that we can hope to / expect to care about future characters as much as we do the ones who were introduced in wc3.