I don't think there was any tether, unless it was linked to the public event style random missions. Any time the tethering came into effect, it was when I was trying to run or fly into an area that was blacked out on the map.
Hmm... there should be no party-tethering in Freeplay. The only time you'll get teleported is if you're hitting the demo zone boundaries.
The intent is that it's for exploration... if you want to just chill and look around, Freeplay is your thing. 😊