No, there shouldn't be any air in there. Even if there is, putting the brakes upside down or right side up will not change anything, especially with the HyRds, since there's no hose and nowhere the air can "travel" to.

Think of the different ways they can be mounted. On the fork they are vertical, in the back, they can lay flat, or be at an angle depending where the frame mounts are.

I wouldn't worry about it. Else there'd be a big warning on the box they come in with an arrow "This side up" ;-)