I find it a little hard to believe that a Pope wouldn’t know who is second in line to the most powerful man on earth, or who the previous Speaker of the House (3rd in line is, especially when they are representing the United States of America and are coming to him.
Oh I'm sure he'll be told that it's the VP but why would he know anything about Biden's faux Catholicism or anything about Pelosi and the American bishops sure as heck aren't going to fill him in.
We like to think the U.S. is the center of the universe but the world is a big place. There are parts of the world where Christians are being slaughtered by Muslims. The Curia is a pit of vipers. The homo-socialist bishops are hanging on to power throughout the entire Church. The Chinese government is appointing bishops. Our national politics are not high on the Pontiff's priority list.