Yes it’s true that knowledge is constantly being refined, with nutrition being a relatively young science. It used to be thought that dietary cholesterol (which eggs are high in) was important, but it is now understood that saturated and trans fats are much harmful for cardiovascular health. And it is not only the US that says this; the latest cardiovascular guidelines from Canada, the UK, Spain, Australia, South Africa and the WHO all say saturated and trans fat intake should be mimimized. For my money, the best bet is to follow the Blue Zones populations (five places in the world where the longest, healthiest people live on largely but not exclusively plant-based diets) as that is something that works in real world settings rather than in a test-tube, a mouse, or mouth of the latest fad diet podcaster :)