virtual races are pure profit, you dont have to close streets have characters hire staff etc. Outside of shipping medals there is no cost. So the ROI for Disney is huge. By having virtual only events (not tied to regular races) they can get the addicts that live close and want to do any race they can, plus the other side of the virtual market the WAY WAY out of towners, people not close to either coast. For me thats oklahoma, I can do virtual races and get some magic as its too expensive to do the actual races often. This doesnt remove any of the numbers from the physical events so there is no harm to the bottom line. All the virtual races are sold out as are the physical ones, so clearly they are all still making money.
I wouldnt worry about them being discontinued. I dont think disney sees them as a competition for the onsite events but a new additional income stream.