Based on feedback from @adamsamec

Environment Information

• Package version(s): 9

Actual behavior:

Currently MenuTrigger only applies aria-expanded="true" and aria-expanded="false". when open and closed respectively

Expected behavior:

MenuTrigger should always apply aria-haspopup="menu"

MenuTrigger should apply only aria-expanded="true" when a root trigger opens a menu. Submenu triggers should apply both aria-expanded="true" and aria-expanded="false"

Documentation describing expected behavior