When a site fails, its questions and answers (plus some other data) are shoved into a data dump, which is attached to the Area 51 proposal. The associated child meta site, however, is not included (unless I'm missing something obvious).
The information on those meta sites could be very useful to people who want to understand why the site failed, so they can make sure their own sites succeed. Lots of time went into meta discussions too, and they're part of Stack Exchange history, so I think it would be good to publish them. I hope that information hasn't been permanently destroyed.
Could data dumps of failed sites' child metas be published, please?