Symbolism behind the human shadows' chain, and the real vs. shadows interactions ?

Narrative of the movie as a whole ?

How does the body swap of Adelaide twist fits in ?

This article asks some questions but at the same time hints the search may be hopeless.

I was about to write that I have no idea, but then thinking about the notion of underground overflowing, here's a quick and probably shaky try :

The suppressed, oppressed part of people from the underground came to the surface and killed their public, untrue and practically oppressive self. The "happy ending" shadows chain would thus imply that society can't be any better without violence to carry out changes, primarily violence against oneself. Finally, helicopters filming the chain could represent a question mark about how this "grassroots" revolt will be presented to the normal audience, assuming shadows have not wiped it out completely and/or they're not now owning the helicopters.

What's your take ?