What are Call of Duty points in Black Ops 4 used for?
COD Points are now available in the game (for PS4, with other platforms coming within next week).
From this Black Ops 4 Reddit post made by Treyarch:
COD Points can now be used to advance Black Market Tiers, access Special Orders in the Black Market, and acquire Nebulium Plasma in Zombies on PS4 (other platforms to follow next week).
It also appears that in the future, other items will be available for purchase, such as weapon skins. But for now, this is not available.