Don't panic!
At Leanpub, we often have authors publishing when the book is 10% or
20% done. As long as the author is serious in their commitment and transparent about how done they are, we think that's fantastic! This is why we have a "percent complete" feature, which is set at https://leanpub.com/YOURBOOK/edit_web_page_status
So, if you have a finished version coming out soon but you've just published now, chances are your book is *way* more complete than most Leanpub books are when they're first published. So you have no reason to panic! :)
We call our approach Lean Publishing, and it's why Leanpub is called Leanpub. The long version of what Lean Publishing is about is here:
https://leanpub.com/lean/read