As far as I can tell, this and the recent change to add watermarking to text outputs[1], is to become compliant with the EU AI Act[2] and CA's AI Transparency Act[3], SB-942[4]. For large enough companies, all generated AI content is required to have watermarking.

[1] https://www.anthropic.com/news/claude-text-watermark

[2] https://digital-strategy.ec.europa.eu/en/policies/code-pract...

[3] https://www.kqed.org/news/12095398/new-california-law-requir...

[4] https://www.leginfo.legislature.ca.gov/faces/billTextClient....