I’m not sure exactly what the problem is that is being reported here, but it works correctly for me. MacOS 13.3.1. C13.0.41.
Cubase correctly follows my system mouse setting for Natural Scrolling and horizontal scrolling in the Project zone behaves the same as horizontal scrolling in the Finder and Logic Pro.
Horizontal scrolling is completely broken in the mix console of course, but in the project zone I don’t see a problem.