Are you sure it is for all accounts or is it just you? If it is for all users, perhaps the country laws of the new owner needs some data which was not needed by the country of the previous owner.
From what I read on their site it is for everyone yes.
AdvCash said on their site : "Please note that due to certain OKPay changes our deposit and withdrawal features involving this service are unavailable until further notice" So I guess even them got caught in this.
I am surprised however that it doesn't affect that many people here since there are no other thread about this it seems.
Once my account is verified I will try the exchanges I was using it with with min amounts first...