According to Bloomberg’s anonymous sources, Sony's upcoming update will enable the PS5's expansion bay, allowing players to install a second M.2 SSD to the console. If you remove the detachable plates covering the PS5, you’ll notice the internal slot meant to house an additional drive. The slot has been disabled since launch, with Sony promising last November that external storage support would come in a future update.
The sources point to this summer as to when Sony will announce the update. That’s nice and all, but Sony hasn’t provided a list of compatible drives approved for PS5.