There's loads of references to other regions in Gen VI. Hoenn actually has very few. Plus the backpacker specifically states he isn't talking about Hoenn.
A few examples:
>Cassius in Camphrier Town mentions how Bill sent him there to work with the PC.
> A non-player character at Magenta Plaza mentions that Professor Oak's grandson visited Kalos to study abroad, and would frequently end conversations with "Smell ya later!"
> A Battle Girl in the Fighting Dojo on the third floor of a building at North Boulevard mentioned that her sensei came all the way from the Kanto region to open a Fighting Dojo.
>Gym Leader Valerie is said to be from Johto.
> Drasna of the Kalos Elite Four claims her mother moved to Kalos from Celestic Town in Sinnoh.
> An NPC in Snowbelle City will play a remixed version of the music from Jubilife City when talked to.
>A Maid who wanders between hotels will eventually trade the player an Eevee from Sinnoh, referring to it as "Mr. Backlot's Pokémon."
> A tourist eating outside of a cafe in Lumiose City mentions having visited the cafe in Striaton City.
> Statues of Reshiram and Zekrom can be found in the courtyard of Parfum Palace.
> A young man at the Magenta Plaza Pokémon Center mentions Team Plasma "making news a while back in the Unova region."
> A man in Coumarine City will play a remix of the song Unwavering Emotion from Generation V when spoken to.
>A woman on 1F of the building with the Fighting Dojo asks about the whereabouts of The Riches and then mentions that she's looking for Miles.
>A Backpacker on Route 10 mentions that Colress told him that the big rocks on that route emit some kind of special energy.
?A Fairy Tale Girl on Route 14 says that she can't wait to finish reading Shauntal's new book.
Sky Trainer Clara on Route 16 says that her hometown is Mistralton City.
