http://www.serebii.net/news/2016/19-January-2016.shtml
Now before anyone panics, this is most likely done because of the wireless Trading and Battles so you don't create Restore Points during one. Probably also to prevent cloning.
The manual for the upcoming Virtual Console releases of Pokémon Green, Red, Blue and Yellow has gone online and has provided a very interesting bit of information. For the Nintendo 3DS and Wii U Virtual Console games, there's an option for you to use Restore Points in the VC menu on the touch screen so you can save a position in a game and return to it afterwards in case you make a mistake. However, it is now confirmed that Pokémon Red, Green, Blue and Yellow are unable to utilise the Restore Point feature of the Virtual Console, as well as being unable to use the 3DS's built in save backup feature.
Now before anyone panics, this is most likely done because of the wireless Trading and Battles so you don't create Restore Points during one. Probably also to prevent cloning.