The buyback of 22 F-5E/F aircraft is in 2020 DoD Budget for USN / USMC aggressor units.
"Moving on to the Navy, one unique item in today's budget materials was the inclusion of acquiring 22 F-5E/Fs Tiger IIs from the Swiss Air Force to fulfill fleet adversary support duties. The 44 F-5N/Fs that are currently flying with two US Navy and one Marine adversary squadrons came from surplus Swiss Air Force stocks. The delivery and refurbishment of those jets
wrapped up roughly a decade ago and the fleet continues to age while demand for its services continue to rise."
https://www.thedrive.com/the-war-zon...budget-request
I expect that some / all will get modified to the current F-5N/F standard with updated avionics and other improved systems that the other ex-Swiss AF aircraft bought in 2006 got.