According to sources close to the Xbox team, and as claimed by Rectify Gaming (via ResetEra), Microsoft has acquired marketing rights on some important games, including Borderlands 3, Cyberpunk 2077, Splinter Cell, Battlefield V, Madden, and Anthem.
To clarify, having marketing rights for a game means having Xbox advertising on them whenever they're shown through videos or trailers, and most likely they'll also be shown on stage during Microsoft's E3 conference this summer. It's also rumoured that among these titles there might also be Shadow of the Tomb Raider and The Division 2.
According to the unnamed source, the list should be 100% accurate, but it's also incomplete, so let's wait and see if more games end up getting marketed alongside the Xbox brand.