Nonsense. I've had two in recent years. Not because I'm concerned with the em but because the master socket is out in the hall, so I run a separate WAP. Back in the ADSL days I had a Billion 7800. Today, on FTTC, I have a Draytek 2762. Both were the non Wi-Fi versions, which are readily available.
The idea that you can't get a domestic grade router without Wi-Fi.
My apologies for the use of the word "nonsense" then.
One could manually take out the wifi antena or the whole wifi board if it was on a M.2 mount for example?
If that's BT's kit, don't forget it's only on loan. It will go down a treat if you start taking it apart. Just buy a non wi-fi unit, as mentioned above.