Hydreigon from Sword & Shield Darkness Ablaze will be the next store promo if you spend a certain amount of money on Pokémon products in participating stores.
It will likely (not confirmed yet, since there is no image to confirm this now) have an exclusive cosmofoil version with the Darkness Ablaze set logo. Also it's currently unknown if the regular version is a Holo card or Regular Rare in the Darkness Ablaze set list.
This is not a Darkness Ablaze Prerelease promo card.
More images and details on how to obtain this card in other countries will follow soon when Sword & Shield within the upcoming weeks. So you are advised to keep your eyes open and check/ask your national toy/game stores during release.