You are partially correct...shareholder action so late in the game will likely not sway the judge (although I always think it can't hurt) and anything not filed by the deadline has even less value. However, the more shareholders get involved, the greater the hue and cry to change corporate bankruptcy laws to make more fair to all.
Corporate bankruptcies are open to the public. If there is sensitive information, it can either be redacted in the filing, or there can be a meeting in the judge's chambers. But individual shareholders and bond holders are often in attendance.