Following the report, some have.

But why be surprised? They grow a lot of greens out of such content. Why kill the golden cow unless you need to (because forced to)?

Facebook banned all anti-vax content 7 months ago, according to the article

They haven't banned it very consistently, according to my news feed.

Setting a policy, and effectively enforcing it, are two different things.

The fact remains that FB were 7 months earlier to this decision, however well they're delivering on that goal.