The 486th Flight Test Squadron is not what it seems. In fact, that's literally their motto. They run secret, classified missions and are used as quick-reaction transportation by alphabet agencies, mostly FEMA. They are spy planes, with a plain white finish and no real distinct markings.
It's strange for this many to be on the move when they are supposed to be on call 24/7 for the department of defense, special ops in the state department, CIA, or foreign emergency support team
These are the planes that have been known to hold association One is at their home base in Eeglin (FL), one flew to DC and is now on the way to Costa Rica, another is in NC after a morning trip to southern AZ, and the last tracked craft has recently landed in DC Worth noting: the callsign on the bird that landed in DC first this morning is BULLA76
Have noted Eglin air activity as being 'of' more than once, they are definitively using Tex's and T38's for non training activity....
How do you provide air-cover/support over your own country without scaring the sheeple....
F22's/F35's would get noticed and talked about but trainers would quickly be identified as such by anyone that knew a little and people rationalizing things to be normal(see a lot of that, even in this place...) would do the rest.
This is a likely explanation for some of them as they are quite capable of filling those roles against anything short of top line military equipment and that is unlikely to be deployed by the DS, at least for the time being...
They can also fill surveillance and tracking roles, they can provide distraction for an area if there is a need to deploys something with sharper teeth in that area, and they can also serve as sacrificial lambs, as unfortunate as it may be a plane taking a Chinese missile and it being an 'accident' is more than likely preferable to a few hundred(or several 1000) people seeing a hidden patriot missile streaking of from a non-military area(or even a military one) to intercept a surface to surface missile(there are also T38 weapons trainers capable of carrying live ordnance...).