From what I understand from here (I live in the Netherlands), handing over your data to US-based companies has been uncertain in terms of privacy for a long time. The US appears to have a lot less privacy protections, and a lot more allowances for the government to access company and user data (especially when non-US persons are involved).

This makes it hard for US-companies handling data of EU citizens to comply with EU privacy regulations. Some legal provisions have been made to facilitate this, but, to answer your question, what changed recently is that the Trump administration recently effectively incapacitated the "Privacy and Civil Liberties Oversight Board" that was central to these legal provisions.

Above is my interpretation of matters, for a large part based on posts by a Dutch expert in these matters, Bert Hubert. In particular see this post: https://berthub.eu/articles/posts/you-can-no-longer-base-you... and this news article it links to: https://noyb.eu/en/us-cloud-soon-illegal-trump-punches-first...