Restoring a crashed website - no longer indexed

I am working to restore a website that crashed several years ago. There were several thousands of pages on the old site, and most of them have been restored. The site crashed so long ago that of course none of the pages are indexed in Google. I'm worried that when I restore the site, Google will slap it, or mark it as spam etc because of the sheer volume of new pages... a good number of the pages aren't high quality. Is there a way I can warn Google about this, or a smart way to go about this?

It shouldn't cause any issues with Google as long as the content is all legal (not copied).

Drip feed the content? Also check and try to find out if the content has not already been copied by multiple websites.
This is the best idea I can come up with at the moment. Drip feed the content slowly.
Also make sure you follow the same URL structure as the old website.