That was more of an intro to Part II.
It basically was to show that whilst Naruto & Sakura were still a mile away from Kakashi's level, they were still a mile ahead of their Part I selves.
So it was more to show that both had made significant improvements and it kinda showed to the readers that we'll never see Team Kakashi involved in low rank fights in the manga since the level of the main cast had significantly lifted.
Naruto's still a Genin. Technically so is Sasuke iirc.
A Chuunin exam would be piss-easy for them if it was done in Konoha. Since Konoha's exam would be a breeze.
As Team Kakashi,
Naruto knows that you don't have to answers the questions correctly in the written exam,
they'd take EVERYBODY's scrolls effortlessly, then knock the hell out of everybody in the fighting rounds.
All judges in the audience would have to give them Chunin rank.
In all honesty, I believe the manga has shown that Naruto had the strength of a Chunin by the time Naruto and Shikamaru's squad went to chase after the Sound5.
He's well into Kage level now.
Or do you think that Chouji or Kiba has shown more inteligence or cunning since the timeskip than Sasuke back then? Hell... Sasuke's and Naruto's strategy to take down Zabuza and force him to release Kakashi from his water prison was pretty ingenious, surelly worthy of beeing rated at least "Chuunin level smartness" if there was such a thing...
Point is, if you consider skills alone, Naruto, Sasuke, Neji, and maybe even Kiba Shino and Lee could be all at Chuunin level... That's just the way they were posted to be...
I don`t see that "balance" thing to fitting Chuunin Exam conception. The strategy is to force opponent to allow yo enter sage mode. Usually naruto have to use few clones to buy a little bit of time to enter that mode. it`s not like something without trades-off.
For that reason alone I dont think it will happen, the exam may not be the only means to go up in rank if you prove yourself without any shred of doubt that you are worthy.
Konohamaru however, who knows, if he has any opponents that can oppose him maybe?
I still think it should be an aftermath or side story though.