You "forgot" one thing (although understandable).
Ash is supposed to return to Kanto (to Pallet Town) like all other times that a league has ended. And the first place that Ash must go in that case is Juniper's lab because Ash has 10 pokemon on his roster and Ash can't take more than 6. And is logical to make a plot aboput a new trainer that intends to take part on the next league when this edition of the league has ended.
Here is where Cedric will say to Ash's friends how going to the White Ruins. Here, Ash's friends will meet N. And it's almost confirmed that Ash and co. will met N in person.