I had a similar issue recently, but with Crystal Palace. There were absolutely ZERO breakfast reservations available for any day during my 9-night stay. There was lunch and dinner availability, but nothing at any point for breakfast. I checked in here and others were having the same issue. I went so far as to reach out to Disney, talked to tech support, who said there were no issues and it was just due to the popularity of the restaurant. I thought it seemed strange, since I've never had this much trouble with Crystal Palace before, and there were still open slots for places like Topolino and Space220.
Something like a week and a half later, Crystal Palace released ALLLLL the breakfast reservations at once. My phone was blowing up with ************ alerts.
So, it COULD be that they're finishing the reno during your stay, but it could also be something like this. I'd keep checking back, because you never know.