Microsoft does not have any exclusive marketing rights for Borderlands 3. This was confirmed by Randy Pitchford, CEO of Gearbox Software, on Twitter.
"Where are you getting that?", Pitchford writes in response to one user who mentioned an exclusivity deal. "Gearbox signed no such thing with Microsoft. How are these things becoming propagated as fact when there is zero basis in reality?"
Earlier this month the rumour emerged that Microsoft had signed exclusive marketing rights for several AAA games, including Borderlands 3, Cyberpunk 2077, Anthem, the new Battlefield, Madden, and Splinter Cell. The original rumour also stated that the list was 100% accurate. According to Pitchford, that's most certainly not the case.