There have been hints like these in the past - this is called foreshadowing. This has happened multiple times in the past, some accidental and some possibly referencing to some new games. A few times this has occurred off the top of my head:
- Outside Mt. Moon I believe in Generation I, there was a little girl that talked about how ugly the Pokemon were inside the cave and wanted a pink Pokemon with a floral pattern. Although this is likely a coincidence since this was five generations ago, but in the Gen V games Munna was created, matching that description exactly.
- In the Devon Corporation Building in Rustboro there was a scientist that is trying to invent a machine that can view the dreams of Pokemon. Hence, the Dream World was formed two generations later.
There are many other instances of this sort of thing, but those are the only few I remember.
If you want a bit of speculation, this could be foreshadowing a new concept in a new game. It's probably not ORAS considering foreshadowing occurs over a few generations, but we might be transformed to Pokemon soon! Or of course, it might just be referencing to Mystery Dungeon where a human gets transformed to a Pokemon. Who knows, but the idea of foreshadowing is much more exciting. :P
They also used foreshadowing to hint the new ORAS games, somebody in the game mentioning that the 20th anniversary gemstone is a ruby, and the 25th is a sapphire. (I think that was what it was, I'm doing this purely off the top of my head) There were many other hints.
But to answer the actual question itself you cannot turn into a Pokemon in X and Y. Sorry. But if you want to know where the surprise is...
It is a carving young Sycamore did on a bench in Couriway Town - it cannot be found with the Dowsing Machine. There are two sets of benches in the northern part of the town, near a woman that gives you a TM. On the right bench there will be a message to Sycamore's future self. Nothing special, but pretty cool.
END OF SPOILEEEEERS
Hope I helped. :)