So most of this is just making things bigger, but ignoring that for a second I'm confused about the inconsistency between the changes to Menus and Active region styling.

The changes for active region styling create a clearer connection between the selected tab and the space it's about. This seems like a very sane change. Then for the menu they explicitly remove that connection, by separating the menu from its button entirely. They also dim the background color of the menu, making it much less clearly separate from everything behind it.