The Supreme Court's order is important because it leaves standing important circuit court precedent recognizing the preemptive authority of the FCC prohibit certain actions by state and local governments that effectively prohibit the offering of wireless communications services. That authority comes from the 1996 Telecommunications Act and the Constitution's Commerce Clause. The Court's order also leaves undisturbed the Ninth Circuit's rejection of Tenth Amendment-related anti-commandeering challenges to the Commission's rules regarding permitting fees, shot clocks for decisionmaking on permit applications, and moratoria on reviewing permit applications. The Ninth Circuit concluded (rightly) that the Commission's orders did not require state or local officials to take action to implement any federal regulatory scheme, but instead they secured a federal right to place and modify cell sites subject only to certain federal constraints.
The Ninth Circuit's decision in City of Portland v. FCC was discussed in more detail in my September 2020 blog post. Free State Foundation President Randolph May and I also discuss the Ninth Circuit's decision as well as the Small Celland Moratoria Orders in our June 2021 Perspectives from FSF Scholars paper, "Wireless Infrastructure Reforms Rest on Solid Constitutional Foundations: Congress Should Preempt Local Obstacles to 5G Deployment."