What are you basing this on. There is no reason to think that it is only for preferred. They are representing all equity. One of the likely outcomes of a settlement would be a conversion of preferred to JPM preferred and resume paying dividends. That way they wouldn't need to come out of pocket with as much cash.
If you read the accusations of WMI against JPMC, conspiring to drive the stock price down to buy the compnay from the FDIC at fire sale prices, it is obvious the US Trustee is there because of this and for the benefit of the stockholders who have been screwed. Should justice be served JPMC will be on the pink sheets and the WAMU signs will be replacing the Chase.