Normally, if the government suspects you of money laundering, they build a case and bring it to court. The burden of proof is on them to prove you’re laundering money or selling illegal goods. Here, they found a way to not only lessen their work load by deputizing private companies, but also affectively gave payment processors a moat and impunity to decide what people can and cannot sell everywhere.
Visa and MC are well within their rights to deny any person for any reason, but the government should have their own processing network. My gut is saying this will never happen since Visa/MC would lobby heavily against it. Even if one is created, expect it to be neutered.