You do realize the preferred shares the government owns can be converted to common, thus diluting current shareholders, right? The only ones buying those preferreds from the government will be TEPCO itself. If you honestly think the government is going to sell the preferreds into the open market, you're completely clueless.
It's pretty clear the D.A. didn't move forward with the charges because of the 1961 law. All parties involved seem to have accorded a true with regards to not mentioning it. Looks like this civilian body doesn't care if the law is invoked. Not only will the executives win the case (wouldn't be surprised if a judge grants a motion to dismiss), but I suspect TEPCO will eventually be included back in that index sooner than later.