the machines need to allow for choice, there has always been a "backdoor/exit/path to Zion" and in this iteration, they have developed this matrix we know as civilisation (in the movie...hehe) and every time they are getting better at it.
what is it that they are getting better at exactly? limiting choice within the matrix.. they need to allow for choice in the program, and without that choice - things fall apart.. think about it.. primitive communism, feudalism, etc.. the choice represents our individualism to some extent. I think in the movie, the word choice is being used synonymously with freedom, however, there are two freedoms. there is a freedom from something and a freedom to do something
the emphasis seems to be on the freedom "to do", within the matrix - and the people who leave chose to leave based on a freedom from.. however the machines still need this in the code.. it is what neo, or the previous ones' would have gone back to explain, as a revelation from God, or a new Red book with rules about how to live.. with psalms and poetry and constitutions.. they need to give people a get-out-clause because without it - no one will voluntarily enter it again, in order for the machines to benefit from our battery-bodies. it's interesting, we must have agreed to this every time before, but every time, the machine's try to take away the 'freedoms/choices' they have given us - until someone comes to remind them
(ref. from conversations with god - great book).
the first matrix was a paradise - Eden? but it was Adams 'choice' that set everything off.. interesting tho, so if Eden is the 1st matrix, primitive communism the 2nd, feudalism 3, capitalism 4 - the architect say 6.. I wonder how the authors have broken up historical materialism but definitely worth a smoke and discussion about. =] Awesome video!