Absolutely brands can lie, there’s no one checking and people can’t tell the difference between lightly corrected leather and true full grain without a microscope. In fact one of the most famous “prestige leathers”, Horween’s Chromexcel is lightly corrected.

However…if we just assume brands are lying then full grain becomes meaningless as well and all we have left is brand reputation.

LL Bean was using the word “genuinely” like Red Wing…it’s like if you went to a fancy restaurant the menu might be divided into simple headings of “beef/sea/chicken/pasta etc” if you read under each plate, you’ll get details about the cut of steak and probably more…the fact that more details exist and are available doesn’t negate the fact that it’s still “beef.” Genuine is the broadest term and can be used legitimately, my take is to look deeper and avoid if you can’t find more info.