The point of this is that I think there should have been some contact. If the Mayans were at a higher level of civilization they could have gone on raids to enslave Aztecs. There was plenty of that kind of warfare going on.
But why would they have mounted an expedition hundreds of miles to the north and west (on foot, mind you, since they had no horses) through inhospitable deserts and tremendous mountain ranges, when there were already thousands of potential slaves within easy reach? Did the Etrurians go looking for slaves in Bavaria? Did the Hittites raid the ancient Kartvelian state of Iberia?
As for the commonalities, ideas can diffuse without direct contact. Did it take Greek-speaking Jews to convert Scandinavia to Christianity? Was it Anatolian peasants who taught the ancient Britons to plant wheat? Both the Aztecs and the Maya drew from previous civilisations which had flourished in the area. The Olmecs, in particular, are considered responsible for originating many distinctly Mesoamerican cultural traits, among them the sort of ritual sacrifice you mention, as well as writing, the 260-day ritual calendar, and the ballgame ulama
by the Aztec and pitz
by the Maya).