It may be an expensive insurance policy, but the shareholders don't have much choice. Therefore, I suspect shareholder approval is a lock.
Got the concurrency of the approval period and the rights offering closing together.
Confused about your last sentence, "PL would never allow an over-subscription priv if the really wanted to buy a lot of the pref.B". Since the pref.B is virtually a forced conversion to common (at least in my view), then why would exercising rights and over-subscription be in our best interest. I may be slow, but my course of action is staring to become much clearer.