[amrcnimgrnt]

I'll leave it to you, a user, that strong EM fields also blind the devices. The signals the ICD is trying to measure are very weak. I can imagine that strong 50/60Hz surge currents really screw things up, especially in single conductor power distribution situations (UK ring circuits, rural farms, etc).

That being said, the article (TL/DR) appears to focus on "static" magnetic fields. The near field charging feature of the iPhone barely makes mention.

I think the "disable ICD" being a simple magnetized reed switch for an implantable medical device is a bit silly. At least tap a code into that reed switch a little!