Perhaps but in this tournament they teams from all over world, I’ve watched Jamaica, Columbia, Morocco, Panama, Haiti and Zambia all acting the same way
See if you can find some old video clips of the U.S. national anthem being played before the 1980 “Miracle on Ice” hockey game between the U.S. and the Soviet Union at the Winter Olympics in Lake Placid. This was arguably the most iconic event in the history of U.S. sports.
I’ll bet you’ll find none of the players singing, and few (if any) even holding their hands over their hearts.