should have just stuck a '3G' sticker over the '4G' logo and be done with it.
literally no-one in the world would have cared if it was called the 'WiFi+3G' outside north america.
Except that some people outside of North America would have asked themselves whether the US model was a different one since the US model was called WiFi + 4G, whereas the European model was only called WiFi + 3G.
Marketing wireless capabilities is simply a mess, not least because 4G means something different to almost everybody. I am not sure what can be legally called 4G, but if there is enough of a consensus that regulatory bodies (and ultimately the courts), that is what you have to stick to stay clear of trouble.