It's actually been confirmed that Nintendo won't be making new eevees unless they are from a new type. This is due to the fact the back when they were making sun and moon that they scrapped their new eevee plans, because of it being to similar in design to a fan made version
People need to learn that the reason we will never get a new eevee type is due to all of the fan made evolutions. Which means the only way we'd ever get a new eevee is for a brand new type to be created
