Yeah Mutants are just normal people. problem is they have powers and are discriminated towards for being different. whether its because they are dangerous or just purely because they are seen as freaks. thats kinda the message. the thing thats holding it back though is the MCU is its already super hero filled. so where is the difference between Mutants, aliens, wizards gods, spider-men, inhumans, vampire hunters, tech men, hulks, and whatever else gets introduced. Mutants will have to be reduced and work in a much smaller way in this universe because you probably could never make mutants work in the way that they worked in the comics. that boat has floated the same way the chances of Magneto being Wandas biological father in the MCU, or Captain america having known Wolverine back during war times has floated. Its easy to create excuses like Xavier has been hiding mutants. problem is when you really start to think about the universe they live in. it starts to collapse under its own weight. and needs to be a case of just don't think about it in order for it to make sense. thats kinda why the chances of them being created in modern day probably would be more likely.