Seems like the bulk of these roles are contract. "$24/hour" was mentioned in the article. Probably no health benefits. Probably no counseling.
251 working days * 8 hours * $24 = $48,192. Less taxes. Less sick days. Safe to assume these workers aren't all going to work out of the main office in SF.
Seems like Facebook would have to set up some sort of work from home system, like people who transcribe medical records, or some sort of off-shore system, to make this work for workers. But... spreading out the people who do this work is likely to increase security risks that sensitive data will be shared, and reduce workers ability to find comfort with peers.
No way to look at this where automation isn't going to be better.