As a local, I would not hesitate to have a blind date in one of the parks if I were going on one. It’s no different than meeting someone at a restaurant, or the movies, or anywhere else. I would actually feel safer, because I know my way around the parks and resorts very well, so if I wanted to lose someone at WDW, I could. If you are staying there do not let them know where, just like you wouldn’t give your home address to a blind date at home.
I am just not into online dating. I would rather do it the old fashioned way and be set up through someone who knows me and the other party.