At the end of the day, even if Thrall serves Sylvanas’ head on a silver platter to Tyrande, even if Tyrande goes full-on “Super Saiyan” and channels her Night Warrior energy to blow up Sylvanas and the Jailer to return to “normal” (for the record, I loathe this word with a passion), even if the Winter Queen magically regrows Teldrassil, etc. etc. none of it will change one simple fact:
That Blizzard honestly thought the Burning of Teldrassil was not only a good idea, but a good enough idea to invest resources into visualizing and implementing into the game to begin with.