When I got to the supervisor for Villains Nite tickets, they wouldn't refund, but they offered a one-day ticket to the parks instead. Technically that may be worth more than the special event tickets, but doesn't do much for us because we have APs. And we can't even get anything handled until after the parks are open.
If you look closely, the language on the website for both Villains Nite and Star Wars Nite doesn't actually offer a refund. It just says call for assistance if you don't want to keep your ticket for the rescheduled event.
We're keeping our Star Wars Nite tickets, but I'm less committed to Villains Nite. I'm pretty frustrated that Disney can cancel an event but not actually refund the tickets (they kept saying it wasn't "canceled," it was "postponed," but what if I can't go to the "postponed" date?). If you get a refund for Star Wars Nite tickets, I'd love to hear about it.