The dongle is compatible with Macs too. Only issue is that you experience some interference if you plug it into a usb-c multi adapter. I resolved this by using a usb extender cable. I've had zero interference since I started using this setup.
To clarify, Logitech makes two MX Master mice - one generic and one "Mac specific" which bundles a USB-C cable and no dongle adapter. On their website, they do not reference the Mac-version compatible with the optional dongle.
