>>29767545>Psychic-type>learns Moonlight and Morning Sun at level 1>seems to be partially based on black holesSeems like a valid theory.
It can't be a mythical because it's found in-game (Deoxys doesn't count because it only became available 12 years after being introduced) and because it comes before Magearna in the dex, who will be officially available for anyone with its QR code as soon as the game is released.
And as far as I know, mythicals have always been released according to their order in the dex.
