ouallou
I installed Houdini 21. I wanted to check out the new features in COPs, the Grunge Map and Shader Presets, but I can’t find them anywhere.

Grunge Map is not there. They said it's going to be released with the next production build. Not sure about Shader Presets.

I believe that tree bark stuff is also due to be released in the next production build - probably early October.