Orbitrack must get it’s satellites from Heaven’s Above vice CelesTrak - HA has the “observer” list and CelesTrak does not.
We do track many of the “classified” satellites - probably a more accurate term is “off the books” - many of those who have orbital parameters that are NOT available from Space Track. The Defense Meteorological Satellite Program (DMSP) was not available from Space Track for a long time but they are hardly intelligence gathering satellites. A number of the actual intelligence gathering satellites we do NOT track.
Then there are the odd ones like SensorSat - it is not an intel satellite but it is one of the “off the books” satellites. We are tracking that one.
I will try to track USA 290 with Heaven’s Above - I tried to contact Tim DeBenedictis to ask about Orbitrack but he has not answered email.