Hello Mike, I hope you are doing well. "A forgone conclusion is a result that is obvious to everyone even before it happens" while the open conclusion is a result which is open to interpretation; the result is ambiguous. I hope it helps, Best regards.

A foregone conclusion is a result that is (almost) inevitable. Everyone knows what will happen before it actually happens.

I have no idea. Actually I never heard about "forgone conclusion". Please someone answer this question.