They lie!
Yes, it was possible until 5th generation and they work on it for the 6th, too.
WARNING: These are non-official tools which aim to be legitimate, but can't prove they really are.
For the 5th generation, there have been tools like PokéSav and PokéGen. With these tools it was possible to create/edit Pokémons on your PC - no emulation software needed. Then again you were able to uploads these Pokémon files to another website, which gave you another DNS adress (an IP) for your Nintendo (3)DS. If you have edited your Nintendos options to that, started the game and looked into the GTS, you were gifted your uploaded Pokémon.
So this can be a possibility that you again create your emulation-Pokémons and transfer them to your gambling device.
I can not recommend this, as I can't tell what happens. You can upload legitimate Pokémon, which may be undetectet. But you also can create impossibly strong Pokémons which naturally won't occure. I don't know what Nintendo does with such bad, bad people. So be aware.
I would recommend you to use Wondertrade or the GTS of the 6th gen. With Wondertrade it's easy to get all starter Pokémons, Evees and so on. In GTS you can search for a desired Pokémon (scroll at the end of the alphabet there).
When Pokémon Bank opens at last, there will be those missing Pokémons, too, so just be patient for them.