I mean they can, yes, at a maximum. The article says "80% of the room’s 54 m^3 total volume being able to deliver wireless power to a receiver at over of 40% efficiency" which means it's 760 watts of uncertain power (because it can drop off further than that). That's more in the range of high power computers... which I guess wouldn't be a concern.

So this could totally be used for a HMD already. I wonder if it interferes at all with data transmission protocols that are used for wireless on the currently available HMDs...