Where's the authority on that?
Ethanol can be used as a temporary measure in methanol poisoning as it temporarily outcompetes methanol in the metabolic process. So it's only useful until proper medical help arrives when better alternatives such as fomepizole are administered. Even then there is no guarantee of success.
Methanol is still metabolized to dangerous formaldehyde and formic acid by the liver's alcohol dehydrogenase. The logic of giving ethanol or fomepizole is to slow down the rate of production methanol's dangerous metabolic byproducts so less damage is done, nevertheless those dangerous metabolites are still produced.
Ethanol's first-pass metabolite is acetaldehyde and it is still toxic but not to the same degree as those of methanol.
It is incorrect to say ethanol is an antidote for methanol poisoning. Using ethanol is a last-ditch stand to try and take some minor control of an otherwise out of control situation. There's nothing subtle about it—it's a blunderbuss approach that often doesn't work well because replacing one poison with a less toxic one is a pretty hit-and-miss process.
Antidotes counteract poisons, that's not what happens when you give ethanol in methanol poisonings.