Andre Ward has refused to participate in the VADA testing

[Freedom]

Upcoming fights

Hopkins has a fight coming up. He's been in the game for 20 years. Is he volunteering?
Kell Brook has came up injured twice for the same fight and is the next gen. Is he volunteering?
How about Abraham?
And Golovkin?
Froch?
Manny?
Rios?
Groves?
Alexander?
Santa Cruz?

All Sauerland boxers including Abraham whose fights are televised by ARD are given Olympic-style testing (random PED testing). It was written into Sauerland's TV contract with ARD.

Hopkins has refused PED testing in the past. None of the others you mentioned (except perhaps Pacquiao) have been reluctant to do PED testing.

Floyd Mayweather has come forward and had random drug testing, whether his opponents wanted him to or not.