In US national team isn't such big, everything is about NBA here. But I think if other teams would give better competition for US in World Cup and Olympics, their attitude soon might change.
There are lots of players options for the Team USA that's why those top calibers don't really forced to play for their country. Unlike in other countries where they really need the presence of their NBA representative to join forces with the national team. NBA contracts also worth lots of $$$$$ so even we don't want to say that those US superstars care for their career, that's how things looked at.
But yes, if ever they will see the USA having difficulty at the international league. These top NBA US players will not hesitate to play again.
About their current roster, still deadly for me even composed of young and new to this competition. Their exhibition game loss during the scrimmage with the USA select team doesn't really alarming. The real action will just be noticed at the actual match.