According to Xbox boss Phil Spencer, part of the reason Microsoft bought Bethesda and its parent company ZeniMax Media was out of fear that Sony might make Starfield a timed PS5 exclusive.
Shortly before Microsoft acquired ZeniMax and Bethesda, Sony secured timed exclusivity for games like Deathloop and Ghostwire: Tokyo. Those deals were honored even after the buyout went through, and it was a full year before either of those games came to Xbox, despite their developers becoming first-party Xbox studios. In the hearings over the Xbox Activision deal, Spencer confirmed that there were rumblings that the same thing might happen to Starfield.
“When we acquired ZeniMax one of the impetus for that is that Sony had done a deal for Deathloop and Ghostwire... to pay Bethesda to not ship those games on Xbox,” Spencer said in his testimony, as transcribed by The Verge. “So the discussion about Starfield when we heard that Starfield was potentially also going to end up skipping Xbox, we can’t be in a position as a third-place console where we fall further behind on our content ownership so we’ve had to secure content to remain viable in the business."
This effectively confirms reports that Sony was seeking timed Starfield exclusivity back in 2020, even in the months leading up to Microsoft's acquisition of ZeniMax and Bethesda. It seems the disgruntled gamers behind that silly 'make Starfield a PS5 exclusive' petition might've gotten their wish in an alternate reality.
Revelations from the hearings today have also included the fact that Xbox hasn't decided if The Elder Scrolls 6 will be an exclusive yet.