I am of the opinion US regulators will be a long way behind...

I am of the opinion US regulators will be a long way behind (gasp, shock, horror - a short arguing a less negative effect than a long). EU I'd expect follow on this year. The RBA/ASIC have a bit of mud on their face with this given their recent decisions and perhaps not until 2022. I was really surprised by the recent RBA decision. Really went against their remit in minimizing costs of payment mechanisms and a level playing field. Suspect they are happy for the passing on business cost of fees in across the board price rises to consumers to contribute a little to inflation.