Board Thread:Questions and Answers/@comment-88.0.101.31-20160810215834/@comment-27384850-20161229040704

From what I recall, their memories of the 200 years (yes that happens) are what get wiped, however everything that takes place in volumes 9-17 are kept. Don't quote me on that, but I believe that's what gets wiped.

Yui's evolution to a bottom-up AI is... unknown. Based on her actions it can be inferred that she did so, however as of yet there has not been any confirmation of such an evolution.