The character breakfast in the park still is, I think, but the price is like twice as much when I did it 2 years ago. I doubt you can eat there without purchasing the character meal deal.
I don't think any of the in park restaurants otherwise serve breakfast, except for the potter ones. You usually need a reservation, but I don't think you need one much any more, if go later in the morning. I've gotten a scrambled egg sandwich from the Boulangerie that was pretty tasty, and a platter, with fruit and a lunch type of sandwich from the C. Moon. Otherwise, probably better to get breakfast from the hotel, or in City Walk if you don't like the food from the potter places. I would guess all the menu items would be available if the place was open. I've been known to just eat ice cream for breakfast, but I hope this helps.