Firstly, this is not a psak. The halacha about arkaos has been existence since time immemorial. This document is not saying anything new.
Secondly, this is just a public proclamation that notes that it has become all too common for disputes to be taken to courts when the first stop needs to be a beis din. This became necessary because the batei din have been far more ineffective than they should be. In many cases, the expected results from a court will be more favorable to one side. These types of situations raise the likelihood that batei din will be bypassed. Whether there is merit to these beliefs or not, halacha does not provide the dispensation to go to arkaos. Only batei din have the option of referring the case.
Lastly, the title of the thread – reporting, suggests the document is about mesira. It is not. It is about arkaos. They are not the same, and should not be confused. The most recent attention to “reporting” within the frum community concerns child abuse, and batei din and the majority of rabbonim have recognized that their resources offer nothing that protects children. There have been similar documents in which rabbonim specifically instruct to report such cases directly. I am not taking a position on this. But it should be clear that arkaos and mesira are different matters, and one is addressed here, the other not.