Back to the topic, I think Duke will keep his spot, but when they start playing someone from another nation he'll get match up against that nation's power player and get blown away and a random MS power player will replace him.
I honestly don't see him staying as a representative to the extent he leaves and plays another nation.
Since they just came back from an Overseas Expedition, they must be at the Camp to stay for a while before the next tournament.
Really want a Court Shuffle in the meantime so we can see some weaker guys. I never loved PoT coz of all the strong characters.
I love Part I because it showed weaker players with really fascinating, unusual or notable playing styles.
(Kamio, Kai, Kikumaru, Chinen, Hiyoshi, Amane etc.)
I don't see Duke or Tohno representing the nation again. Ohmagari I won't rule out.
Since Ohmagari has had more significance than former Rikkai man Mouri so far.
Mouri who should have had history with Yuki, Sanada, Niou and all the other Rikkai regulars has yet to be seen talking with them off the court.
My point is, if somebody like Mouri who should have so much relevance the MSers has been fodderized so easily I don't see a lot of these HSers having relevance in the storyline for long.
I can only see Byoudouin, Tanegashima, Ryoga, Tokugawa, Oni and Irie sticking around.