Thread:Extension talk:VisualEditor/MediaWiki Required Version

Is there a reason VisualEditor now requires 1.23wmf2? I didn't see anything in the status updates stating what was changed in core that causes it to require the alpha development version. I would like to start testing on MediaWiki 1.22 with the idea of allowing my production users to try it, but it currently throws an exception stating "MediaWiki 1.23wmf2 required--this is only 1.22.0rc2".