Do you have a source for that last sentence? All I can find is the opposite:

<<Universities around the world have reported seeing an uptick in applications from U.S.-based researchers, who face an increasingly uncertain climate under President Donald Trump’s administration. And some countries and their institutions are already looking to use the opportunity to attract new talent and reverse the steady migration of scientists to the U.S. in recent decades.>>

https://www.science.org/content/article/overseas-universitie...