score:5
No, it has not been widely adopted by Reformed churches, mostly because in many ways it requires beliefs that are seen as matters of liberty of conscience in the older confessions. Ironically, it is also more "ecumenical" than the Reformed confessions in a few areas.
After a cursory review, here are a few significant points of difference with older Reformed standards:
There are relatively few people in conservative Reformed circles who could subscribe to all these statements. And even among those that could, many would see them as matters of liberty of conscience, and thus would not prioritize finding fellowships where these points were affirmed.
Another indicator of the lack of widespread acceptance is the small number of signatories, and perhaps the relatively high percentage of independents and baptists listed also indicates that this document is tailored for a specific subset of Reformed believers. It is certainly not broadly representative of the views of those holding to Reformed theology.