"Originally released for the Game Boy™ Color system in 2000, Pokémon Crystal makes its return on the Virtual Console on January 26th, 2018. Explore the Johto region again—or for the first time! Available only on the Nintendo 3DS family of systems."
Nintendo has already bought the original Game Boy games to the 3DS as digital downloads. If you cannot wait to get your hands on Crystal you'll be able to purchase Pokemon Red, Blue, and Yellow on your handheld through the 3DS' Virtual Console right now! You can also relive the days of Pokemon Gold and Silver and they too are already available!