FlyerTalk Evangelist
Join Date: Nov 2018
Location: Istanbul, Turkey
Programs: TK Elite Plus,BAEC GGL,ITA Executive, AFKL Gold,QR Gold,HH Diamond,Bonvoy Gold,ALL Gold
Posts: 14,186
Both sides, the UK & the USA haven't changed their policies yet.
This is only a trial for voluntary passengers.
Passengers who wouldn't like to take part of the trial could still board these flights without a test ( As far as I understand from post #1 )
In UA, United rebooked passengers for free to another flight if they wouldn't like to participate in their trial program.