Bing indexing is not a by-product of Google indexing
The two crawlers make independent decisions, and it is entirely normal to find a site comprehensively indexed by one and patchily indexed by the other. Because Copilot's web answers are grounded in Microsoft's index, a page missing from it cannot be cited no matter how well it ranks elsewhere. The first deliverable on this service is usually a Bing coverage report, and it is often the first time anyone has run one.

