It is probably the best way Cindy can punish Casey for enlisting, re-enlisting, and sacrificing his life for the USA. It must drive Cindy nuts. Actually, by the looks of it, it has.
Interesting thought, and something about what you just said does really click and lock into place.
She could not and now will never be able to punish her son for betraying her and enlisting, so now she punishes him in absentia.