that's just it, there is no flush interval. it's listed as inspect fluid level every 8k kms for us canucks and nothing more.
it does list 40k kms as severe use in mexico to flush the brake fluid. severe use in the US is only inspect fluid level. use your judgement on that one, from my experience here and with other cars that's usually excessive.
most of the time the dealers will tell you what is 'required' maintenance. rarely do we check against the official maintenance schedule. remember, the dealers are there to make money, not be your friend. so when you stop and think about it, the people who designed and built your car came up with this schedule to keep it running. the dealer just wants business. as far as warranty goes, the dealer only facilitates the warranty - despite what they would want you to believe they do not dictate the terms and conditions of the warranty.
so if a dealer is 'recommending' certain service that is not part of your schedule, think long and hard about it. i like to tell people "never trust anyone with a motive that does not coincide with your own". the dealer wants your money, so therefore i don't trust them until proven. the manufacturer wants me to buy another mazda one day and they know it being reliable will be strong persuasion so the manufacturer is more trustworthy in this scenario.