They are curated. Probably around 5% of the generated content was usable. As someone who has been responsible for coming up with content for twitter accounts I can say even with having to curate the results it was still orders of magnitude faster than having to write original content. It took around 4 hours to generate about 3 months of Twitter content.

Fascinating! If you're the owner, I suggest mentioning the ~5% in the twitter profile.