It looks like rather than using the WHO tests and guidelines, the CDC decided to develop their own universal SARS test and completely bungled it. It correctly detects SARS-CoV-2, but gives false positive readings on other viruses, so they were only allowing a few state labs to run the tests:
https://www.propublica.org/article/cdc-coronavirus-covid-19-test
It turns out the CDC is the swamp too.
The CDC decided to develop their own universal SARS test rather than use the WHO guidelines that everyone else is using. We could have been testing using WHO guidelines all-along while they fixed their test.