I've seen people discuss what should happen in future adaptions with Magneto, as we get further away from WWII and the Holocaust. I think that origin shouldn't go away at all. And there are ways to keep the idea that he's an Ashkenazi Jewish Holocaust survivor intact. Of course, comics don't really have to address it with the sliding timescale and all. People understand that. You don't have to constantly update with war a veteran character served in. You could always do to him what happened with Steve Rogers, but I don't think that's the best idea. Or follow Evolution's lead and say he used machines. But I think the simplest way to do it would be to just say that his magnetic powers can keep his cells from oxidizing like metal. And you could even keep the way he and Charles met in Israel somewhat, as antisemitism in the world and violent attacks on people there are still sadly prevalent. So, he could have been working in a hospital there any time really after one of Arafat's Intifadas or any of Hamas' campaigns. I still hope Fassbender can reprise the role in the future. He's so great as Magneto.