I don't understand why this suddenly happened (except if asked by the USG in response to the recent scare/reality over rare earths).
The 50% ownership by a sanctioned entity was a reality for a while, and was an issue as soon as the purchase. This didn't change recently. So, this action should have been part of the pre-purchase review (CFIUS in the US...I assume there is an equivalent in China). On the face of it, this all could have been avoided by having a non-sanctioned entity (including another random Chinese company) own enough of the company to get sanctioned entity ownership below 50%.
Definitely US pressure. NL is always eager to get on the good side of the US, even if they get nothing in return. For example participation in the war in Iraq and Afghanistan and Gaza today.
The 50% ownership by a sanctioned entity was a reality for a while, and was an issue as soon as the purchase. This didn't change recently. So, this action should have been part of the pre-purchase review (CFIUS in the US...I assume there is an equivalent in China). On the face of it, this all could have been avoided by having a non-sanctioned entity (including another random Chinese company) own enough of the company to get sanctioned entity ownership below 50%.