I have a Standard Page asset. It has 2 bodycopy divs. I make the Page live with cascading status. Divs become live. Later I add 2 more bodycopy Divs to it. Is the expected behaviour for them to be "Under Construction" or should they assume the status of the page they are linked under by default?
Point to note is that when you change the status of the page, it changes the status of the child Bodycopy DIVs even without the "Cascade" option.
New DIVs are created under construction - like all assets. You have to go make them live yourself.
Standard page status changes change their DIVs because they are all dependantly linked (like a user/workspace/inbox as well). This is normal behaviour.
I guess the dependent linking should suggest that the newly added asset is to assume the parent's status, not the generic asset status. As you say, similar behaviour is implied in the case of existing dependently linked children. As I understand the dependent linking means that the child is almost meaningles without the parent.
Dependant links do not mean the child is meaningless. DIVs are shared between pages - so its obvious that they cannot reply on one parent for meaning.
Dependant links indicate that some changes (like status changes) that occur to one asset should be applied to the others.
As for creating as the same status as the parent - this is another issue that has been discussed in the past. We just havnt had a chance to look into how this will effect other parts of the system or if we need to make this a bodycopy only thing (as I suspect we do).