A couple of things to keep in mind:
1) Always be careful giving dairy to children on board an aircraft if you do not know if they get airsick or not. While dairy won't *cause* airsickness, it will make it much more unpleasant if it does happen. While a bottle to clear the ears is a great idea, clear liquids are better for a child with an iffy tummy, though you will have to buy them airside or fill a sippy/bottle from an airside water fountain. Do NOT trust the air crew to supply bottled water, most aircraft do not have much of it on board, and you really don't want to give a baby water from the aircraft holding tanks.
2) As far as "You are encouraged to travel with only as much formula or breast milk in your carry-on as needed to reach your destination" -- I would advise you to interpret that liberally if your child isn't old enough to eat airport-vendor junk food. My personal rule is that any time I'm traveling with a baby, my carryon MUST contain 24 hours worth of food, drink and clothing for that child. Getting delayed in the terminal is bad enough, but you never know when you could get stranded on a runway; I've been there with a baby, and it isn't pretty. It gets VERY hot on the aircraft when you are stranded on a runway, and the kids invariably start getting sick tummies.
In most airports, the airside vendors sell whole, skim and 2% milk in half-pint cartons, plus apple juice in pint bottles. If you plan to purchase milk for a flight, bring along a lunchbox-sized insulated bag and several empty ziploc freezer bags. You can get ice from an airside restaurant or bar to fill a couple of the bags and keep the milk cold. (Best to double-bag ice.)