It looks like Arkane Studios Austin, an Xbox studio, started development/incubation on Redfall around August 2017.

If Redfall makes its Summer 2022 release, the game has been in development for 5+ years, full production obviously less than that. https://t.co/hfv3xwLxMx pic.twitter.com/mHDmy3CCpE

— Klobrille (@klobrille) June 25, 2021