Does it ever get the racoon poop on the stick fungus clumps on its branches? Chokecherry also only has a single stone in the fruit vs buckthorn which has multiple seeds. Buckthorn will also have an orange-ish inner bark color if the outer bark is scuffed.
Yes Greenstick, Chokecherry does look very similar, but the leaf veins don't quite match and the bark is darker like cherry tree or cherry blossom bark. Also as you said, the wood from chokecherry is darker than the paler Privet wood. But yeah, there are a lot of little trees that sort of mimic this tree including Autumn Olive, however the color of the berries are too red.