PrePub of The Reformation Study Bible & Interpretation

I was curious about 2 prepubs:
The Reformation Study Bible, I own this one in Logos already, I have looked at the notes and found there was no difference I could see. Even the pages on CBD seems to indicate the only addition of maps to the text. Perhaps there is more to that. But with the second one the Intepertation series was nearly complete in Logos format years ago, when it got pulled, shouldn't that mean only a few files need updating and 3 or 4 new books need to be added????
-Dan
PS: I am just really curious about the process, I would love to own Interpretation in Logos but as I already own the complete set electronically published by JKP, and I have already been told there would be no upgrade option. http://www.cokesbury.com/forms/ProductDetail.aspx?flid=2660