I decided not to implement that feature. As it is right now, many people are still getting confused and believe that the update notification email is sent out by a mailing list on AkeebaBackup.com instead of their site. I know that the sender address says otherwise, but I even had a moron who reported HIS OWN EMAIL ADDRESS for spam and cc'ed me the email, calling me several colourful things and threatening me with legal action for "hacking his site" (the update URL, he considered "hacking"). As a result, adding a feature which would further make it more difficult for these users to properly identify the origin of the email is a no-go.
At the same time, when you receive an update email, all you have to do is to go to https://www.AkeebaBackup.com and click on the latest release announcement link, right below the login button. There I analyse with great detail what are the changes in this release and paste the Changelog at the end, thus helping you to perform an informed decision. I believe this is the best approach.
That said, I will add a link in the Live Update page which allows you to see the Changelog directly.
Nicholas K. Dionysopoulos
Lead Developer and Director