It may be a long time before we really know anything, but more than likely your right they are saving a lot money by not filing. They may drop to a no info tier also, and run it like a private bus.
But the last two deals, Dominion/Con-Edison, which WERE stated as consummated, apparently opted out, as it would seem, which is an additional issue. All that being said, they are public whether they like it or not and really need to provide some info.
just out of courtesy since the pps is to low to matter anyway.