Do you think the following opinion about Amazon.com is true?

I think Amazon.com writers are retiring ebooks from the market and concentrating their efforts in selling the paper ones.

I think this because, for example, “Operation Snowdrop” by Michelle Medhat, an important prequel of the series “The Trusted” isn’t available anymore as an ebook. The prequel series “Lost decades of Uncle Chow Tung” by Ian Amilton is available only as paper/hardcover or something, certainly NOT as ebooks. So, you must explain me.