I need a better explanation of how Iron Man remains neutral while MOS is too much set in the real world. Iron Man (and the rest of the MCU) went as far as to establish real people, real politicians, and real life issues (i.e. terrorism) as present in the universe. MOS has yet to do such thing. If anything, the MCU is much more like the real world at the moment due to that. The only difference is that the MCU has generally a lighter tone, giving off the impression that it is more realistic than it really is.
The only realistic thing about MOS - other than establishing that real-life companies/convenience stores like IHOP and 7-Eleven exist (which Marvel did too) - is the way the general public reacts to superhumans existing. Even that isn't fully realistic either. Superman gained the trust of the military pretty fast compared to what would have been the case in real life. I doubt the government would wiretap phones to look for his secret identity (which is what would happen if Clark Kent was real) and although people may fear Superman to an extent, he will gain people's trusts far faster than he would in real life. Thus even the most realistic thing about MOS is toned down in comparison to real life.
To answer one of your questions, can I picture magic existing in The Terminator? No, because the Terminator is a sci-fi film. However, I can maybe see it (if executed properly) in a crossover film between the Terminator and a more fantasy character. In the same way, I don't expect WW in MOS because MOS is a Superman film and there is no room for WW for magic elements to be part of the story. However, I can see magic existing in a crossover film between Superman and Wonder Woman such as JL.
Look at this this way. We live in a very science-driven age and the vast majority of the human population still believes in a God or Gods. This means that most people can see science and magic co-existing in the real world. If people can accept them to co-exist in the real world, why would most people not accept them to co-exist in a fictional universe that does not have to be bound by reality?