classes that keep certain artifact traits/ abilities do that at the cost of existing talents (the only exception is unholy dk)
dh will be more than fine with their absurd utility in addition to damage, it won't be the same as it is now with all your legendaries to get the spec to work, but that goes for every single spec in the game, so stop whining.
the class was freshly designed and they clearly don't have clear concepts for the gameplay, otherwise they wouldn't have changed it around so often in legion and they would have implemented a third spec, so don't get your panties in a bunch that they change stuff, since it was incredibly obvious that it would happen ( as it does with every single spec in the game)