Quote from Cainsson »Yeah but they put a quote of his in the guildgates and he opposes Domri while Nikya supports him. Which breaks the cycle from every other guild having two legendaries with opposing views that have quotes in the guildgates. So I don't expect consistency in GK RAV/RTR/GRNA representation when they can't keep it anywhere else.
My understanding is that Nikya does not support Domri. Although they're both set on razing the city, their philosophy is very different. Nikya is deeply spiritual and believes that the razing of the city is a sacred event, and that the full destruction of Ravnica must not begin until Ilharg appears (at which point the End-Raze will happen and the world will end). Domri's approach is entirely secular. He doesn't care about the Ilharg prophecy, and he doesn't want to bring about the end of the world: his plan is to entirely destroy the social structure of Ravnica and start society again (with the wilds restored and everyone forced into a Gruul style of living).