Forget about "expected". That would mean you would dance with or against an build-in metronome or memory. But actually that occurs and occurred. Watch that milongueros of BsAs that enter a milonga at a certain time to dance the same certain piece for the hundredth time, unable to dance (sic ! dance ) to unknown music. All the same with the golden age music. Show stars like d'Arienzo and Biagi found approval with a mixture of confirming and confusing the audience. Real interpretation isn´t aware of anything like syncopation, traspie or the like!