Default ARIA role for dynamic container is given as "main" in below article. But when I add a dynamic container to a section, the default ARIA role set is "presentation". Is the article correct or the system behavior?
I ask this because, the screen layout's center panel's ARIA role is "main". Since most of the times, the section with dynamic container will sit in the center panel of the screen layout, can we assume assistive technology would navigate to dynamic container for "main"?
I cannot tell if that is a documentation bug and/or if we have changed our default behavior. A product owner or SME would need to respond to confirm.
But I can confirm your findings, and in my eyes the current behavior is correct. In most cases your portal is designed with a screen layout having a center panel. And this center panel would traditionally be marked "main". This main center panel section also would typically have a dynamic container. So if the DC was also marked "main" that would be redundant and cause a duplication of "main" regions.
So to bring it back full circle, I believe your reported behavior is fine. But if you feel the need to override this default for a unique reason, then it is there for you to customize.