Here is an update my daughter has just been sent in PRG. I was going to try to get her to swap out the LHR-JFK leg to LHR-PIT, but that won't be possible as they have to fly into certain airports. (I'm retyping this from a screenshot she sent me from her iPhone, bolding is mine.)
Following the announcement from President Trump concerning the 30-day suspension of travel from Europe to the U.S., the Department of Homeland Security released a clarifying statement regarding the exceptions to the ban indicating, "This does not apply to legal permanent residents, (generally) immediate family members of U.S. citizens, and other individuals who are identified in the proclamation." While the ban does exempt American citizens and permanent residents, the acting Secretary added, "In the next 48 hours, in the interest of public health, I intend to issue a supplemental Notice of Arrivals Restriction requiring U.S. passengers that have been in the Schengen Area to travel through select airports where the U.S. Government has implemented enhanced screening procedures."