My guess is that the Western community is pretty perplexed about this new development. So while this is certainly an important piece of information, it cannot be celebrated, since a China-Iran-Saudi relationship is potentially a huge risk to world order—from a Western perspective.
It would help Iran evade Western sanctions and develop its military and weapons production, and China would be less afraid of sanctions—if it chooses to attack Taiwan, and the Saudis can just agree to a nuclear Iran or even buy an arsenal of their own—making the whole region more dangerous.
On the other hand, how can you denounce "Peace"? And what would the West achieve from denouncing it—as it is still trying to get the Saudis to stick with the US while absorbing rebuke on civil rights matters.
So downplaying the whole event, hoping that it won't develop into warmer ties and security cooperation, is in the best interest of the West.
In regards to internal US politics, this can be seen as another severe foreign policy failure of the Biden administration, and of the whole ideology that a weaker America is better for the World (if Ukraine and Afghanistan are not enough)—as we all know, some news outlets don't like reporting such types of information.
See https://www.gatestoneinstitute.org/19492/biden-pushing-arabs-towards-iran