Many people visit this village for Día de Muertos, both tourists and locals, and some people claim it's becoming too touristy. I still think it's a great spot to visit - although there is in some aspects a carnival atmosphere, you will still find quiet spaces where family members remember their loved ones. There are many photo opportunities here, but try to be discreet, and ask for permission to take photos.
There are many other cemeteries to visit in the villages around Oaxaca. Different villages celebrate on different nights, and some cemeteries are only open during the day, but may still be worth a visit to see how the graves are decorated.