Orderer node data view / centralization

Hi,

I have been reading the offocial Hyperledger Fabric documentation several times now, but still have some questions about Orderer nodes.
This is from the 1.4 document.

On page 32 (4.4.7) it describes a network with Org 1, 2 & 4. There is one orderer node controlled by Org4, then org 1 & 2 creates a channel where only those two orgs have access.
However, Orderer node is naturally also connected to the channel (it is the only orderer node).

My questions is, what kind of data view have Org4, through the Orderer node, to the data being sent between Org1 & 2 in this scenario? Is there any security risks? Orderer node is hosted on Org4s network, can this be abused by Org4?

Maybe this is just for illustrative points in the docs, but how would this have been solved in a real-world scenario?

I am a bit concerned about centralization of power. I read this https://developer.ibm.com/articles/blockchain-hyperledger-fabric-ordering-decentralization/ , but is not totally convinced....

Thanks!