What happens when the Mac OS menu bar fills up with too many icons? When the Mac OS menu bar fills up with too many icons on the upper right side, and begins to encroach on the space of the menu text, will the OS begin to make the menu bar taller and wrap the icons?  Or will the icons simply overflow / overlay the menu text?

This question assumes that Bartender is not installed.
You can test it by changing your display resolution ;)

low resolution -> overlay



normal resolution