Is a proxy object linked to original ?

Hello, I have several characters in distinct blend files and I would like to create an animation with them in a new blend file.
Then I create a new one, linked my files and chose “make proxy” to be able to move the bones.
I thought the proxy objects where still linked to their model but after changed some little things in a character’s file I saw the modifications where not applied in the final file.
Then my question is, do I need to update the proxy object in some way or if it’s not linked is there something else than proxy for doing that ?


An update shouldn’t be neccessary.
The rig is possibly not set up proper for pipeline.

Thanks, in fact I think not everything can be linked. For example if I move a vertex or a bone in the library file the changes will be applied to the destination file, but if I add a constraint to a bone it wont be added.