Sram Red AXS Crank Bolt Cap missing - how to remove crank, if at all?
Yes, it's true!

The design is known as a self-extracting crank, you can find some excellent videos on how they work, by searching online. You'll see on page 24 of the installation manual that when the crank is removed in steps 1 and 2, it has the little cover with the four small holes in around the crank bolt (where yours is missing). The crank bolt turns against this cap to drive the crank off the spindle. The crank bolt might be nice and tight, but it is designed to be turned. 

There isn't any other good way to remove the crank. Some people might remove the bolt and then start hitting the crank until it falls off the spindle, but I wouldn't do that unless it was a last resort to save a bike with a crank which will be scrapped.