I think this is the usual thing where some engineer/scientist has developed a product that's interesting and put out a press release then a journalist got ahold of it, grossly misinterpreted what was being said and wrote an article speculating that this would lead to all kinds of things that are not even remotely possible.

The article claims this will somehow save money on wiring a house, but that emphatically does not seem to be the case, that's not the problem being solved here. This isn't a revolutionary breakthrough, this is just a slightly interesting design to power IoT devices via wireless power rather than the usual dime batteries.

I wouldn't call it "harvesting" if you have operate power transmitters on each floor of the house. "Energy harvesting" usually means you are using something that is already present in the environment.

"each floor would have one or two RF (radio frequency) power transmitters to powe r up all switches inside the house."

I imagine replacing the battery in your light switch in the dark (because you can't turn the lights on) is probably rather annoying. This sounds like a cool idea.