This is being made out as a win for patients, but it actually IS NOT. I'd describe it more as a win for insurance companies and potentially patients, with the losers being the out-of-network doctors, depending on the situation. This does have the possibility of reducing the quality of care around trauma in the US.
We have a few competing forces involved in surprise medical bills (really, out-of-network bills).
Insurance companies that negotiate to obtain in-network rates with medical providers (Doctors mainly). Insurance companies regularly negotiate based on a multiple, or fraction of medicare and medicaid rates.
Doctors, and practices providing care. Most doctors are either hospital employed (RVU compensation), or in a private practice. Doctors want to get paid fairly for their services, and there are some with extortionary rates, normally because they are handling the shit work that is not profitable with an in-network model.
Hospitals that are the locus for much of it via ERs. Hospitals don't want to employ doctors because they are overstaffed on administrators already, and, RVU based compensation does not equal financial viability. They prefer to punt to contracted practices that handle parts of the care, leaving the hospitals with the fat facility fees that provide much of their income.
My wife's practice has negotiated in-network rates with every major insurance (and they try to be in-network with everyone) for a multiple between 100% and 200% of medicare. The practice is clearly geared towards reconstructive in-network care and the surgeons work 9 - 8 regularly. One of the nearby plastic surgeons' practice is focused on trauma plastic surgery, and they are completely out of network. They charge between 500 and 2000% of medicare and they don't have regular hours since their trauma plastic surgery work is based on car accidents and workplace injuries which regularly come in at night and odd hours.
Whereas the compensation for an 8-5 cancer surgery via medicare rates would have most practices in the red if 100% of the practice, performing them at multiples of medicare rates are sufficient. For a trauma practice though, the regular compensation (based on codes and billing) for a nighttime surgery don't actually reward the surgeon well enough to gear their practice around performing that service.
I think what would be a better approach would be to cap out-of-network practices at 500% of in-network rates and call it quits. This would disincentivize the practices shooting for 2000%, and also, not reward the insurance companies that would shoot for a 50% to 75% of Medicaid, not Medicare, if they could get away with it.