That card is worse than you think actually.DM decks already has lots of way to summon DM and this card is a trap and needs a dm in hand to activate it in the first place.
As others said, until we get Eternal Soul (and maybe even with it) I don't see DM having potential to be meta. This is a great card, but by itself won't change the meta, as it's a trap and you have to have a specific monster in hand to activate it, so it's not that easy to use, and in a current meta with cards like Red Eyes Fusion and Neos Fusion, it lacks the speed and versatility to compete