ngl, personally I would have hated an ending like that. That falls under the "it was all a dream" type of scenario, which may have once been cool and original, but these days it's often a cop-out. Basically it renders the entire story pointless. All the pain and suffering our main characters went through? Oh, well, let's say it never happened! If you're going to have an ending that rests on Seerow making a choice, you can't keep it a big secret to pull out of nowhere. That totally undermines the story and characters we got attached to over the course of over 50 books.
The way I see it, you would need to introduce Seerow and this situation earlier, perhaps even start with it. And then, throughout the "what if," you would need to return to the reality to sort of touch base with the core conflict. You would need to show reasons why Seerow might even still choose to give the Yeerks technology. Then at the end when he makes the decision, that decision effectively carries the weight of the story.
Basically, the whole series would need drastic changes, and I still probably wouldn't have liked it as much as what KAA/Grant gave us.
Just my opinion, of course. I am in the minority that liked the ending--it had its problems, but for the most part I liked it.
