If you followed the link in that email it took you here where it describes what will be happening and provides links for information on how to select a price, Discount & Promotional Pricing Guidelines, and Setting Prices Responsibly. This was all available 7 days ago. I don’t really know what extra information you could have wanted.
It would have been nice to know the day it was going to start, but it wouldn’t have changed anything for me personally. I wouldn’t have done anything differently if I had known the exact day.
Edit: I also received an email last night, and it was also addressed to the wrong author, so they definitely goofed there!