I think what is going to happen initially is that complaints will continue to be filed against presbyteries or sessions that attempt to ordain practicing homosexuals, adulterers, and other candidates engaged in sexually immoral behavior.
Nothing in the new non standard authorizes a departure from the requirements of Scripture and the Confessions, which specifically condemn sexual immorality, including homosexual sex.
We need to call PCUSA to account as to whether they are explicitly going to reject the authority of Scripture and the Confessions. They can't just pretend to sweep it under the carpet.
You're right that standards haven't changed, and ordaining bodies are still accountable. However there are different kinds of accountability. The previous rule was in the Book of Order, which is essentially procedural. Violations are handled by Permanent Judicial Commissions, which in practice seem to be lawyers. The confessions are typically interpreted by presbyteries, sessions, synods, and the GA. The PJCs don't want to get in the business of making theological decisions, nor do they want to evaluate specific candidates.
My guess is that most PJCs would reject the previous complaints, on the grounds that the Book of Order wasn't violated. Further, under the new rule, ordaining bodies evaluate candidates as individuals, and can make judgements that in this particular case the candidate is acceptable even through they are a sinner. The PJCs typically wouldn't want to accept a remedial case based on either a theological interpretation or a judgement of a specific person. They get involved primarily on procedural matters. Indeed I believe there have been cases already where they refused to review judgements on individuals, as long as the procedures were followed.
Thus I think accountability would be to the main bodies: presbyteries, synods, the GA, as part of their responsibility to maintain accountability of the bodies below them. As far as I know, that would be based on patterns of decisions, and couldn't be used to reverse individual ordinations, because that review wouldn't happen quickly enough to deal with a specific case.
The situation I'm describing is not new. It's the way the PCUSA has normally worked on most issues. To my knowledge, no PJC cases have occurred based on adultery, premarital sex, or anything other than homosexuality. The process before G-6.0106b was added, which is what we're returning to, does have accountability, but not in a way that would typically involve intervention in a specific case, although there's nothing in principle to stop a body from intervening in a lower body's activities.
There is one more kind of intervention that is still possible, which is a disciplinary complaint. All the existing cases have been remedial cases, trying to stop an ordination. But it's perfectly possible to issue a disciplinary complaint against someone who is already ordained, based on behavior in violation of Scripture or the confessions. However there would be practical difficulties in documenting their private sexual practices.
in my view, the new process will continue to allow bodies to review actions of bodies that report to them. But challenges under G-6.0106b weren't typically of that nature. They were individuals who disagreed with decisions of bodies trying to force action as a legal matter. That type of intervention is now going to be difficult, if not impossible. I think that's a good thing. The current mania for law suits in secular society has created all kinds of problems. I'd rather not use the same process as a Church. Someone who doesn't like how bodies are behaving has every right to complain, either to the body or one above them. But the PJC process goes around that normal accountability. it was designed to stop procedural abuses, not to deal with theological disagreements.
