From the different sources we're hearing, there's roughly 45 minutes of pre-alpha footage from Call of Duty: Black Ops Cold War being passed around the internet focused on an early map build simply called Tank.
Here is some Call of Duty: Black Ops Cold War (COD 2020) Pre-Alpha gameplay.
With Activision delaying the new seasons for Call of Duty Mobile and Modern Warfare, expect to see a similar delay on a proper reveal for Call of Duty: Black Ops Cold War until later this year as well