The implications could be enormous for every site on the Web that competes for Google ranking. Good UX is more than look and feel. Make sure you have a seasoned UX professional on your team to maintain a strong Web presence.
Google can currently look at the user interface and not just see specific font sizes but see how a user would see the fonts on different mobile devices. Google is also able to see how a user will see how a page scrolls on a mobile interface; are the buttons large enough to click on; is the interface confusing to mobile users?