Last modified: 2012-11-15 00:25:34 UTC
Possibly the wrong version of Parsoid updated? See https://www.mediawiki.org/w/index.php?title=VisualEditor:Test&diff=next&oldid=604180 as an example of '<p data-ve-changed="[...]">' elements being created.
Fixed in https://gerrit.wikimedia.org/r/#/c/33410/