It says "up to 90 days out". While all other bookings are solid at "up to" 180 days out, this means that Disney can release the breakfasts anywhere between 1 and 90 days out. So it could be 60 days out or 33 days out, etc. Its all in the wording and they have all dining worded so that its not exclusive to be set on a certain day (even though all others are). My guess is that it gives them wiggle room for when/if they have last minute decisions to consider. At least thats my interpretation of it.
When the breakfasts were extended to Oct 3, I don't think it was at the 90 day mark.