Ditto to what
@cgattis said -- they are double walled, but honestly don't keep things cool real long in the sun...not at all like a hydroflask or Yeti would. Not having a chip means you can go refill to get a cool drink or there's nothing to stop you from transferring it to something better insulated.
Just a note for those reading this later -- the ones by Ulu are the only Coke Freestyle machines (the others by the center gift shop and by Ama Ama are regular fountain dispensers). So if you want (many) more options, especially for sugar/caffeine free, you'll want to head to Ulu. There are 3 machines there, along with 3 ice/water dispensers, so last week when we were there I never felt like it was too busy.