Btw - the hours of operation for OBB nights show Dinner from 4pm-5pm.
Last year, I got an 8:15pm ADR for an OBB night. (At the time, I thought they might do a themed World of Color, and that it might be nice to see it from there. I hadn't been to OBB before, and hadn't thought about what I would be missing.) They called me to inform me it was during OBB, and I confirmed I had a ticket.
I ended up cancelling it when I realized what a bad idea it was. They may have realized that it wasn't worth it - especially with the ADR confusion with non-OBB guests.