WMI won't come out of bankruptcy until they are ready. As long as there are still assets to be determined who is the owner, and L>A then they'll stay right there. Receiving the $4B as it is already listed on their books won't change a thing, it will just move it to an account that they control, and get it out of the hands of the enemy! And that's a good thing.
I do believe that WMI will put together their bankruptcy exit plan after they receive the $4B, but that doesn't mean they come out immediately. The plan will be a beginning point of negotiating with all parties, JPM included.
This post is my own opinion, and should not be relied on for your investment decisions.