We saw it last weekend, so it is running. It runs multiple times an evening. Just so you know, they funneled us out of Hogsmeade after the show, and we had to walk around again to enter. Not a big deal, but maybe plan on seeing it at the end of your evening when you are ready to leave.
I also found it confusing because it wasn’t specifically listed anywhere in the website. Only the darks arts show was listed, but I think that was seasonal.