welcome to the base man.
The recent chapter had a huge content which was squeezed into just 17 pages..so a lot of small details were skipped..you should assume any facial expression you want..
When you have Hashirama, Tobirama, Hiruzen, Minato, and the Juubi on the field, as well as Madara shown to be psychotic when it comes to Hashirama, people should learn not to be surprised.
its as i thought. seems to be naruto's friends came to know from their parents that his father is 4th but they never discussed among them cause may be to keep safe naruto from his fathers enemy as the 3rd hokage did.