How do you know this? I was able to reserve a non-character breakfast on a Monday this month. I just checked reservations and put in a Monday, it still says "character breakfast not available this day." So as far as I can tell from the website, Mondays in October are still non-character days.
I don't mind if it's a character breakfast, but our kids didn't care, so I picked the day that worked best and cost less. Hopefully we'll only be charged for a non-character meal even if it has changed.