In this online video, Google’s Matt Cutts answered the question: If your website has an archive of hundreds of thousands of pages, should you add these pages at once or in stages? We know you probably don’t have 200k pages, but this is good info on building out your website. You might be better going live with a new website sooner, and building out the new content over time.
Google Answers: Is it better to add website content slowly?
Jul 9, 2017 | Google