Well, if you look into the documentation you can see that to support dynamic size you have to use the new UIFont methods introduced in iOS 7 on an object. To not support dynamic size, you would probably have to change the font of the said labels to a fixed size. That being said, The MapKit Framework provides no way to change the font of these labels to the best of my knowledge. However a quick web search pointed me to the MKOverlay and MKAnnotation classes as the only thing related to font and MKMapView.
UPDATE: As Pointed Out By Apple(https://devforums.apple.com/message/931571#931571) the only way to change it is to adjust the font labels, using the new API's in iOS 7.