Issue with published_at being set to null on publish

[kanaabe]

I haven't been able to replicate the issue, but Matt Domino reported that an article got published without a published_at date. This seems impossible given the API will set the published_at if it is being published and we haven't changed that logic in a long time.

These two articles were affected today:
https://www.artsy.net/article/artsy-editorial-art-therapy-helping-people
https://www.artsy.net/article/artsy-editorial-sold-fiac

[halleyjohnson]

https://www.artsy.net/article/artsy-editorial-alex-strada-contractually-binding-collectors-support-emerging-female-artists