There are dozens of Bitter Dreams skins. 52 to be exact, if I get it correctly. Each week has one skin on offer, and the full rotation takes more than a year. Imagine missing one skin and then missing out on the weekly when it is obtainable the next time. See the issue?
Instead of having a fixed rotation of rewards for everyone, the game should determine the reward for the CW weekly on a per-player basis, picking a Bitter Dreams weapon skin at random from those that the player does not have yet.
Thank you for your attention to this matter.