The FCC just released its report on the October 2023 National EAS Test.  The report, which comes from the FCC’s Public Safety and Homeland Security Bureau, can be found here (https://docs.fcc.gov/public/attachments/DOC-403500A1.pdf).  Here is their high level summary:

The test message was received by 96.6% of EAS Participants (increase from 89.3% in 2021).

The overall retransmission success rate was 93.6% (increase from 87.1% in 2021). This significant improvement is likely due to initiation of the 2023 test alert via Common Alerting Protocol (CAP), which introduced additional resiliency that was not available during the over-the-air-only 2021 nationwide test.

• While test participants reported less than one-third as many performance complications as compared to 2021, more test participants reported equipment configuration issues and equipment failures.
• At the time of the test, approximately 23% of EAS equipment units representing over 4,500 EAS Participants, were either using outdated software or were using equipment that no longer supported regular software updates. Test results demonstrated that fully up-to-date equipment had the highest receipt and retransmission rates (97% and 95%, respectively), whereas equipment with software that is no longer supported had the lowest receipt and retransmission rates (90% and 85%, respectively).
• Five of the six poorest-performing geographic regions were U.S. territories.  These territories were the Northern Mariana Islands (20.0% retransmission success), Guam (33.3% retransmission success), American Samoa (66.7% retransmission success), the U.S. Virgin Islands (88.9% retransmission success), and Puerto Rico (89.7% retransmission success).

Based on these results, PSHSB recommends that the Commission adopt rules to improve the operational readiness of EAS Participants and Participating CMS Providers, as well as ensure that EAS Participants are installing software updates in a timely manner and have plans for replacing equipment that is no longer supported by the manufacturer. PSHSB also recommends actions that EAS Participants and Participating Commercial Mobile Service Providers should take to improve the reliability and reach of WEA and the EAS, including in the territories of the United States. PSHSB also recommends that Congress require all CMS Providers to support WEA.

Looking inside the report, the importance of AM/FM radio is apparent as those broadcasters largely outperformed other participants in receiving and relaying the test:
Read the full report from the FCC here.