Some are 'educated' more than others, but they can be called.
Case in -point: My hunting partner has been 'working' on a family unit for a year now. He has pitched anything and everything(except turkey calls) at them to no avail(digital and mouth calls).
He challenged me take a crack at them, so, I took him up on it.
Got setup, put the FX5 at 30 yards in a two acre open patch in a russian olive grove, waited 10 minutes, hit 'lost hen' at vol. 15 for 3 minutes, then switched to 'excited hen' at vol 20. 5 minutes later I see what I think is a deer following two fawns in the trees. Next thing I know? its two coyotes being tailed by a whitetail doe. the bi%^ stayed in the trees and the old dog came out at 150 yards for a look see. Had him dead to rights. NOT a good shot so I held off and he eventually meandered back to momma and the pups. No foul, no errors, no hits, no home run. Still there. Gotta get a hen turkey decoy now and call them from a different spot. My partner was fit to be tied.
I believe ALL coyotes can be called. You just need the right inticement to make them respond.