Tough to do this within the constraints of academic freedom; if an institution wants to offer a new course and they need to get certification by an authority and find externals to mark it... well could stall things by years?
There might be more enterprising universities that launch courses quickly (and would probably still reserve the right to do it with things like masters courses), but most undergrad courses take years to develop and deploy anyway, so an external body reviewing the content and assessment criteria wouldn't hold things up much in comparison.