I think you're referring to a sale that did not go through. I remember reading about that not too long ago. I assume that potential sale in particular is what led to this change.
Edit: I read the article. I was mostly right, except the sale did go through but the land had to be sold again promptly.
The expansion comes less than two months after a previous CFIUS review handed a Chinese-linked company and its partners 120 days to sell property they had purchased one mile from a U.S. Air Force base in Wyoming that is home to part of the U.S. nuclear missile arsenal.