Even if they didn't want to have an overflow menu for some reason there it boggles my mind why the menu bar isn't just aware of what portion is covered and should be skipped (file menus or icons) in the first place!
Well there's effectively no space on the lefthand side of the notch. You must assume that side is going to be completely consumed by actual menu items.
Side note: If you want to check what icons might be buried by the notch, you can Cmd + Drag any icon from the menu bar to rearrange them. If you drag an icon through the notch, the other items will pop into view, if any are hidden.
Well there's effectively no space on the lefthand side of the notch. You must assume that side is going to be completely consumed by actual menu items.
Side note: If you want to check what icons might be buried by the notch, you can Cmd + Drag any icon from the menu bar to rearrange them. If you drag an icon through the notch, the other items will pop into view, if any are hidden.