Messaging Extension role in the grounding process

Question

Assume the App Manifest version for a partner Teams app (and messaging extension) is upgraded to enable copilot integration.

The user interacts with copilot to ask a question. The extension queries the partner api and database.

Metadata and text/file content will be returned via the partner api. Is this information considered in the grounding process?

If this is the case, then there is less of a reason to utilize a Graph data connector. Correct?