Besides, all that gelatin would gum up the buttons of the ebook readers.
Anything about Rowling is book news, and in particular, given her known antipathy towards ebooks, a new book by Rowling is ebook news
because it won't be an ebook. Officially.
(Though I'm considering starting a betting pool on how many days in advance of the paper release the fully scanned, OCR'd, and proofed version will be available via darknet.)