I suppose it really depends on what your definition of breakfast includes. If you are talking about something that approaches the food options at a resort CS, then Sunshine Seasons is really the only in-park restaurant. And it is not any better or worse than a resort food court.
If, by breakfast you mean stopping by the drive thru at McD's for an egg mc whatever and a coffee, then yes, you can get something at any of the parks. I'd tend to call that something else, but yes, the places listed by the PPs will give you something to eat in the morning.