I’m actually curious as to why you would purchase a WiFi enabled speaker system when you’re concerned about EMF. I’d think there were a lot of wired options that would be a better choice. 

Perhaps you should invest in an EMF measuring device. Here is a discussion.

And you might want to purchase a Faraday blanket.

I am suspect of EMF meters being advertised/evaluated by a website which has already designated any and all EMF as "dangerous".  Something tells me the more "dangerous" EMF it "detects", the better the review.  No EMF wary consumer is going to be satisfied with a unit which gives them nothing to be wary about.  Heck, if I were an unscrupulous businessman prone to picking on the mentally ill, I'd peg the meter in the red and sell it as the most sensitive one known to man.

In my opinion none of the reviewed instruments are lab grade, but they should be able to detect ON, and OFF. While it requires some skill to correctly use this sort of instrument, it would be possible to rank devices measured with the same instrument.

To answer your question: the fact that the setting “WiFi off” switches off all WiFi connections, which I suppose means all WiFi, is actually a complained about a lot because it also switches off the dedicated 5Ghz link between soundbar and surrounds/sub.

BLE (Bluetooth Low Energy) used for set up cannot be turned off it seems. Would not all electronic devices send EMF though?

Yes, even a flashlight. Our task is to determine at what level the fields become threatening to biological processes.

I would think the FCC already accomplished that task.