Does MS365's eDiscovery Content Search use SharePoint's crawl index to perform searches or does it perform it's own independent search? And if it does use the crawl index, then if you exclude a document library from being crawled, does that mean the eDiscovery Content Search wont find that library or any of its contents?
Microsoft 365's eDiscovery Content Search operates independently of SharePoint's crawl index. It searches content directly within supported data sources, including SharePoint Online sites, without relying on the existing search index.
If you exclude a SharePoint document library from being crawled, it will not appear in SharePoint's search index. However, since eDiscovery Content Search does not depend on this index, excluding a document library from crawling does not prevent eDiscovery Content Search from accessing and searching the content within that library. Therefore, eDiscovery Content Search can still locate and retrieve items from the excluded library.