The US Government can declare that the companies involved must come up with a way to provide equivalent functionality when interoperating between platforms, and then the companies can figure out how best they want to do that.

Then every day that's not the case after a grace period, or without convincing evidence they're working on it, they can eat fines or sanction from the FCC.

I don't care how they solve this problem, just that they do and that's what effective regulation is about.