if you speak to him once a day for 4 days he gives you an item called strange souvenir that is made to look like a pokemon that protects the region and a maid in the hotel tells you it would be awful to throw away gifts so this thing seems kinda important and after he tells you the region is NONE of the regions in the games so far serebii has some info and screenshots of it if you wanna check it out
and also to every one saying there wont be dlc i think they meant paid dlc there could still be event downloads like the torchic one or even one that unlocks a region to visit in game? i doubt it but i dont see why the guy would give you an item in x and y thats meant for a whole other game.
My Strategy guide has the info on ALL the visitors for the hotels.
There is a Hiker that Trades you a Magikarp, he's from Kanto.
There is a Garcon that gives you a Rage Candy Bar, he's from Johto.
There is a Madame that will give you a Lava Cookie, she is from Johto (she is the main one that is giving the Hoenn references that I've seen)
There is a Maid that trades you an Eevee, she's from Sinnoh.
There is a Tourist that will tell you about the Gym Leaders, they are from Unova.
The Backpacker that gives you the Strange Souvineir is from "An unknown Region"
So the Backpacker that says, my town/facility, you'll see in due time is a reference to a NEW region and not Hoenn.
To get the gifts/info you have to talk to them daily.
So the Backpacker in the hotels is not a Hoenn reference.
I did see the painting before too. So we have the Madame, the painting, and the couple that talks about anniversaries. That's three references that I've found. Still looking for the swimmer...So four. I think I've run into 5 mentionings of Sinnoh. I'll have to go back through and talk to all the NPCs again...but I think they will all actually even out at some point.
But sorry to debunk the backpacker...I just found info on him in the guide.