> - it's related to the annouced GPS disruption test (although that's a really long time and doesn't seem urgent enough)

Those are done regularly without TFRs. See recent example in Texas:

* https://avbrief.com/overnight-gps-testing-affects-huge-area-...

A link to a list of notices at:

* https://www.navcen.uscg.gov/gps-service-interruptions