The menu components are "Menu, MenuItem, and MenuGroup" and should be "Menu, Menu.Item and Menu.Group" instead which is more explicit about the context where they should be used.
Test that the menus are working in the same way that was before.
The menus affected are:
Admin console dropdown menu (at the top left)
In the admin console the group details menu (with group sync enabled and with groups configured)
In the admin console teams management, the dropdown for actions of the team.
In the admin console users management, the dropdown for actions of the user.
In the channel menu
In the channels members list (manage members) the dropdown menu for each user
The dots menu in the posts
The main menu in the main window (LHS)
The user status selector in the main window (LHS)
In the manage members for the team, the dropdown menu for each user