I don't have an answer for you since I don't know either but will add that this would be a great feature. I would love to see it implemented.
Thank you for posting. We're striving to improve the reading experience and your input is valuable.
Below is the ebook suggestion thread that we currently use for ebook requests:
Is there a way to sign up for an alert on a p-book, so that when the e-book version is released, I know I can buy it?
Yeah, I would love to have an alert for this sort of thing to arrive on the daily when I use my Nook!