Here, from Railway Age, is a provision in the infratsruture bill on reductions of service:
Section 22210 is headlined “Protecting Amtrak Routes Through Rural Communities” and essentially reaffirms prior policy. It says: “Discontinuance or Substantial Alteration of Long-distance Routes: Except as provided in subsection (c), in an emergency, or during maintenance or construction outages impacting Amtrak routes, Amtrak may not discontinue, reduce the frequency of, suspend, or substantially alter the route of rail service on any segment of any long-distance route in any fiscal year in which Amtrak receives adequate Federal funding for such route on the National Network.” This is essentially the established policy, but a new provision, §22210(d), requires 210 days’ notice to members of Congress who represent states or districts where the discontinuance would occur. Presumably this provision was added to prevent another sudden service reduction, like the cut in long-distance service to tri-weekly that began last October and lasted until the beginning of this past summer.
I suppose they can try to claim maintenance outages due to lack of staffing in their maintenance facilities but I am not sure how they can get away with reducing trains to tri weekly under this law, especially without adequate notice to members of Congress.