All phones and iPods mess up a transceiver when searching if they're within a foot or two, so no real surprise that a GoPro does too.
But they're really testing the wrong scenario (unless you like filming your friends from the top of a line with a GoPro, or ski avalanche terrain in a group). What I'd be more interested in seeing is to test what would happen if my buddy gets buried while his GoPro is running, then I search for him. I've asked Facewest to comment, they're pretty good with this sort of thing.
They should test all POV cameras, now that most of them have a wifi function on them. Seems like they could interfere with the becons. i have no Idea if it could actually affect a beacon but it would be worth testing.