When big companies, institutes and political parties use the word 'proactive' it generally means find a way to limit the damage and then find a way to hide the problem.

> The paper also quoted a 2019 internal report from Facebook, suggesting that the social media giant knew about, and had been investigating, the online slave trade before the BBC got in contact.

The article seems to conflict itself on this subject.

proactive in terms of legislation/gov't investigation. if some news platform asks about it and even publishes something about it, it means nothing to FB. it's not like their users are going to stop. if the gov't looks in, it could mean that a new toothless wrist slap fine could be coming.