For players who want to dive deeper into the details of update 1.5.6, here are the full patch notes:
Following this update, Odyssey was officially classified as a "Legacy Title," which meant all original UPlay rewards were unlocked for free for all players, while active weekly challenges were disabled. Technical Details Deployment Date: December 14, 2021. Patch Sizes: PlayStation 4: Performance: ac odyssey 1.5.6