The question isn’t if this would be a good mutual ending, the question is what consequences this end would bring to WOW as a whole.
Being objective, this leak sounds likes a preparation for a massive revamp or WOW2. Its very easy to sell the idea that time in Shadowlands flows in a different way, so we can easily say that when we was doing our jobs in Shadowlands 25 years have passed in Azeroth and a new generation of leader have emerged and the World have changed drastically.
The one point in this leaks that make me think its not a complete waste of time is that it points to a reset in WOW. I think that the devs make it clear that they want this expansion to be revolutionary in some way, and the way they could make it right is to revamp the world, and make things goes faster. I would love to see a new generation of leaders and nations being add’d to the game. And would be nice if the people in Shadowlands could return to life after we do the job there, and being forced to adapt in a world thats complete different of what they know. We can even have the idea of reorigination made by titans a thing after Shadowlands. So the big question isn’t what would happens if this leak is true, the interesting question is what would be a 10.0 patch.
This would make the lore engaging again for me.