IANAL, but I would not want to deal with the headache of underwriting whatever plan you're thinking about. Who would they be buying this insurance from? What specifically could it be protecting against?
Seems much more likely that they'd need to seek restitution against the producer of the planes through civil court channels. "You sold me a faulty plane/didn't explain what your product did well enough and now you need to refund my money" but on a multi-million dollar scale.
Insurance for loss-of-use is quite common (edit: in other industries—no idea for aviation), though it's normally (AFAIK) for natural disasters and other random occurrences. I wonder how the purchasing contracts between Boeing and the carriers are structured—perhaps they have a warranty that would do something similar.
Seems much more likely that they'd need to seek restitution against the producer of the planes through civil court channels. "You sold me a faulty plane/didn't explain what your product did well enough and now you need to refund my money" but on a multi-million dollar scale.