I counted all the campaign missions, there’s actually 66 campaign missions if you count every single one. Blizzard, there’s actually 66 Campaign missions in Warcraft 3.
Here’s the ones they did not count when they said “62 missions”.
Curse of the Blood Elves
Secret Level: The Crossing
TFT Custom Campaign; Exodus of the Horde
Chapter Three: Riders of the Storm
Chapter Four: The Fires Down Below
Chapter Five: Countdown to Extinction
The last three are right now not accessible unless you bought the games a long time ago. If you don’t have the last three chapters of Exodus of the Horde you can download them. They tell the story of how the Darkspear Trolls joined the Horde, how Sen’jin died and why the Darkspear hate the sea witch.
Suggestion: Players unlock the last 3 chapters of ‘Exodus of the Horde’ into the Campaign list after completing ‘The Scourge of Lordaeron’.
This is done similar to how Founding of Durotars campaign missions unlocked one by one after completing the other campaign missions.