Global Site Search Content Display

If I have my network locked down for administrators only during development, when I make my site live will all existing content be searchable by the Global Site Search plugin? (and global tags plugin) - or only new content??

If the answer is no, is there a way to fix this? We are building in a lot of content prior to going live, and we want it to be searchable from the moment we go live. Is it a case of re-publishing the content again once the site is live or is there an easier way?

thanks for your help.