K.A. Applegate - It's all about contracts
Jeff Sampson, (owner of MORPHz.com) relayed the following quote from K.A. Applegate about the mysterious Megamorphs #5:
This is what K.A. told me about the cutting of Megamorphs #5 on October 17, 2000:
"Anyway, on to the saga of the missing MEGA. It's all about contracts, actually. I had signed a contract for 6 ANI long-form books, meaning Megas or Chrons. And I had, at a different point, signed a contract for the last bunch of regular-length ANI's. But the two contracts weren't synchronized, so the due dates of the long forms extended well out beyond the due dates of the regular-length books. Then I decided to pull the plug on the series, leaving Scholastic in something of a quandary as to 3 long-form books.
"One of the long books we agreed to make a series bible. Another one was going to be a 'whatever happened to . . .' kind of book to be published a year out in the future. And the third one would be a final Mega to be published (according to the regular schedule) at the same time as 53. Fine, but then I realized 53, 54 and the Mega were all going inevitably to be one, continuing storyline. So how do we get kids to realize Mega and 53 were in sequence when they were published at the same time? We then agreed to move Mega to run at the same time as 54, hoping that would clarify things. But Scholastic sales and marketing guys had different plans already in the works. And let me say that I love Scholastic sales and marketing, they have done very, very well for me.
"Anyway, I think (though I do not know) that sales was concerned that two ANI books in June would step on the release of REMNANTS at the same time. These plans are all made long, long in advance and involve all sorts of details and arrangements, and my messing with the sequence wasn't helping their lives any. So we all jointly decided to take BOTH the final Mega and the 'Whatever happened to . . .' books and add them to the REMNANTS contract.
"I am not personally at all upset. I think the finale is fine the way it's going, though I understand that some readers may have wanted one big, final MEGA. Still, I think they'll get some of that in 54."
Orginally posted here [deadlink]. Referenced here July 2002
Michael Grant - It's all about math
However, co-author Michael Grant says that the preceding story is not true, and that the answer was really just bad math.
Why does the 'A Letter to Fans' in Animorphs #54 say that there are five Megamorphs books?
That's because neither @kaaauthor nor I should ever be trusted where numbers are concerned.
Does it have anything to do with cancelled books? (I read somewhere that there was a 5th Megamorphs planned that got turned into a Remnants)
No, that's def not true. Our EVERWORLD contract for 20 books was turned into REMNANTS 'cuz EVER was hard to write.
Don't know how accurate this is, but Jeff Sampson had quoted @kaaauthor as saying that Megamorphs #5 got added to the Remnants contract.
I think it's just confusion over the conversion of the EVERWORLD contract. At least to the best of my memory.