Are block annotations supposed to be instance-specific ?

Are block annotations are supposed to be instance-specific ? If I change a block annotation in my lib, changes are not propageted to all my blocks in my project ?

[Kaustubha Govind]

To provide some context: http://www.mathworks.com/matlabcentral/answers/46657-how-can-i-show-all-block-parameters-in-my-project