First thing I did when I read that was to put rub something all over my tongue just as a sanity check. When I tried to tell someone they went bonkers trying to defend the school book. From that point on I never took anything school books or adults said as fact without evidence.
I don’t think outdated maps is as important as other things. Because two reasons. Maps are expensive to replace, and maps are politics. So no matter how you print the map, someone will think it’s wrong.
Now if they thought you this knowledge about the maps, that would be really cool.