With the release of Modern Warfare®, Infinity Ward is set to deliver the greatest amount of weapon customization ever in Call of Duty®. Providing more options and player agency through weapon customization is another part of the Call of Duty franchises commitment to the community, which also includes the introduction of crossplay, the removal of Season Pass, and plans to release more free maps & content post-launch to keep the community together.
Source: N4G PC A Deeper Look at Modern Warfare Customization