From what I understand it was more that they found a sympathetic ear in the management suite at Mastercard and Visa. They've been wanting to do this for some time but needed political cover.
Ideological alignment with the party in control of the US executive, legislative, and judicial branches gives groups like these quite a bit of leverage.
My guess is none, and that they are only used as a front for this. It really doesn't add up that a "grassroots org" from Australia that doesn't even have its own Wikipedia page can pressure Mastercard / Visa to pressure Steam to remove games. Makes zero sense.
