Arkane's Harvey Smith says a planned PS5 version was scrapped following Microsoft's acquisition of Bethesda.
Three armed people walking through a deserted small town in the fall. The sun is eclipsed by a dark shadowy orb.

Redfall is an upcoming cooperative FPS that will have you and up to three additional friends roaming the town of Redfall slaying vampires. Redfall was announced as being exclusive for PC and Xbox platforms, which does make a lot of sense seeing as how the developer, Arkane, is owned by Bethesda and Bethesda is owned by Microsoft.

In an interview with IGN France, Redfall game director Harvey Smith revealed that there was, at least at one point, a PlayStation 5 version of the game that was planned. Prior to the game being announced, Redfall was planned for PlayStation 5 in addition to Xbox, PC, and Game Pass. Obviously, once Microsoft acquired Bethesda in 2020, plans for the PlayStation 5 version were scrapped.

"We got bought by Microsoft and that was a huge sea change. They said, ‘no PlayStation 5. Now we’re gonna do Game Pass, Xbox, and PC'."
Smith continues on to say that he and the team didn't particularly have any issue with this decision. To him, this just meant "one less complexity" to worry about.

"Support from Game Pass and have to worry about one less platform, one less complexity. And Game Pass has a ton of people that can play. It could be our biggest game ever because of the 30 million Game Pass [members] or whatever that number is."
Games that were announced prior to Microsoft's acquisition of Bethesda, such as Deathloop and Ghostwire: Tokyo were released on the platforms they were announced for. Both of those titles just happened to be timed exclusives for PlayStation 5 and PC.

How this sort of news will factor into the Competition and Markets Authority decision on the Activision Blizzard acquisition remains to be seen. That whole thing has been a long, drawn out process that has seen Microsoft agreeing to deals with Nintendo and Nvidia, and even extending a hand to Sony. Meanwhile, Sony's CEO has seemingly admitted that they want to block this merger from happening and that the fight has never about keeping games like Call of Duty on Sony platforms.