Brexit also had a 10% shift in currency value as soon as the markets could react to the news.
I don't know how big a deal this news is on the markets, especially given everyone's already trying to shift to renewables. And it might have been predicted in advance, unlike Brexit where the markets expected Remain.
I think Brexit was also more obvious. The effects and timelines were more clear, there were stronger, and well-publicized opinions, and so it was easier to predict what would happen and hedge accordingly. This time of predictability also creates a self-fulfilling prophecy environment. Having people bet against makes things harder.
These news on the other hand seem more abstract. There's no deal now, but the Saudis could change little in the way they do business. They could also change a lot. Other players have cards in the game too— China could start pushing a petroyuan, it could be well-received, or maybe not. There's a lot of actors in the world trade of oil, and the global use of the dollar— plus the latter depends on much more than just oil trade.
With so many questions in the air, I'm not surprised nobody is making strong bets on what will happen. And perhaps this even leads to little happening in the short term. I guess time will tell.
I don't know how big a deal this news is on the markets, especially given everyone's already trying to shift to renewables. And it might have been predicted in advance, unlike Brexit where the markets expected Remain.