He did not say it did happen, he said it easily could.
But it really couldn't.
The historical Christians who didn't understand it was symbolic thought it was just a communal ritual - and in fact, some historians of the antiquity think that it's how it originated (eating bread together as a form of bonding, by opposition with sacrificing meat to the emperor) and only later on it was interpreted according to the words of the christ.
In fact all variants of christianity clearly state that the human body is sacred and should be preserved. There are condamnation of cannibalism against all the people who practiced it, and all the people who were suspected of doing so, like steppe people (for example the Magyars in Regino's chronicles in the 9th century). Cannibalism in post-roman cultures is always perceived as against nature and something the worst pagans/barbarians do. There's zero chance cannibalism could have been a thing in the christian middle ages.
Accusing catholics of cannibalism only became a thing much later with the Reform (and then by psychoanalysts), and nowadays it's also a joke.
In Europe, accusations of various kinds of anthropophagy have been made against various groups through history, though it has nothing to do with them being christian or not. It's just a way to dehumanize enemies. It's also a reason why it's so hard to believe travelers of the Age of Discovery when they describe Amerindian tribes as cannibals - maybe it's just a way to show that they aren't completely human.
A lot of people on these forums are impregnated by protestant ways of thinking so I'm not surprised that so many of them think that catholic cannibalism could be considered a serious thing, but it's still a myth.
Which doesn't mean that I'm against a cannibal tenet in the game, but come on, it's clearly a joke.
