Technically, they aren't lying when it says for use with New Horizons. They do work with the game to give you special posters. I don't imagine they would cut out those posters and replace them with the villager posters if we did get the villagers.
Ideally, this would be a sign that we might get the amiibo characters back, but I'm not counting on it. I personally don't want to get myself hyped up only for it not to happen. I would love for it to happen, but it probably won't.
Oh definitely not! They could easily get away with it, so long as they aren't making false promises about amiibo characters. I'm just saying that it would be one of those instances where something really fantastic COULD happen, but Nintendo just says "here's some pixelated pieces of paper to put on your wall, knock yourself out kiddo."