Last year, Google released the first-ever Pixel feature drop, which added a number of features to its lineup of devices including Automatic Call Screen for the Pixel 4. This is an expansion of the original Call Screen feature introduced with the Pixel 3, and as the name suggests, it automates the process of screening calls.
Automatic call screening can be enabled to the extent that the user prefers, and as you'd expect, it focuses on numbers you might not trust. There are separate settings for spam calls, private numbers, first-time callers, and possibly faked numbers, so the feature will only kick in in the situations the user chooses.
Once call screening kicks in, it works just like before, and users have the choice to save an audio file of the screened call and change the Assistant's voice for calling. If you'd like to enable the feature, Google has a pretty thorough guide on how to do it.