I cook in my dutch ovens all the time, and that includes chili.
It is one of my favorite ways to cook, my ovens get a real workout over the length of the outdoor cooking season, and seeing how I live in the desert, that is about 10 months long, I mean forget it in July and August
a well seasoned cast Iron dutch oven will just laugh at the acid, remember the seasoning is a layer of carbon, that is what protects the iron and makes it non stick.