In that case, they are clearly misleading the regulators, because they know Bloodborne and Sackboy are first-party games, even if developed by external studios.
More importantly, Microsoft themselves use the term "first-party" for first-party IP games developed by third-party studios. Here is an example (Ori and the Will of the Wisps Fact Sheet).
This sheet can be downloaded from the official website xbox.com.
Here is a direct download link.
So either (1) Microsoft doesn't know what they are talking about in these documents, or (2) they are intentionally misleading regulators by presenting Sony's first-party exclusives as third-party exclusives.