Will the content of the old Literature proposal be re-imported into this one?
Not automatically, no.
If there are some questions from the old Literature proposal which you feel are particularly good and worthy of being on the new site, you can always manually re-post them on the new site (preferably with attribution to whoever posted them on the old one).
Robert Cartaino explains this here:
generally speaking, you don't want to start a new site with questions imported from elsewhere.