Yes, some people did get their visa changed without waiver, that were just by chance, or you can say by mistake. They will face same trouble when they apply for GC. At that time, it will be much harder to get a waiver based on "no objection" since they will not in an active J1 program, one of the requirements for J1 waiver.
If you want to stay, I will suggest your hu*****and find another institute and do a J1 transfer. By doing this, you will get more time to get a waiver. Otherwise, you can take chance to apply for a visa from a third country and pray VO will make a mistake again, but chances are your application might be denied and you could not come back.