The Magic: the Gathering Standard Domain Ramp deck archetype is continuously evolving on the adjustment to the current metagame. It is justifiable as new strategies arise to counter the deck build in resolving Atraxa. Given that it has already acquired a powerful card in Cavern of Souls, which makes the Phyrexian angel uncounterable, the deck would still be open to new components. It is maybe easy for them to do so as the Domain lands build makes it flexible to almost any color of the card in Standard.