The "full bundle" is a bundle of all available paid content at the time of its release, hence the word "bundle". This bundle simply allows you to purchase all current paid content and save a little money, when compared to buying each individual expansion separately. The old bundle (which you own) couldn't possibly have the Redstone Atlas Pack bundled with it, because it didn't exist when the old bundle was made. The new bundle includes the pack as it is a new full bundle with all available content, and is priced accordingly.