WOW Air stops flying without notice. I think this is the traditional view, perhaps to prevent individual creditors from attempting to tie up an aircraft prior to the filing of the general bankruptcy. We already have a question from someone who can or can not get a refund.
The mass market travel insurance that I've studied in general excludes the insolvency of an airline from its coverage. Since I buy tickets with a credit card, I can certainly recover the rate of unused flights through a chargeback. However, I am curious to know what insurance would buy replacement tickets on another airline. None of my travel insurance cards cover this. Are there players in this niche?
Some of my summer vacation flights can be done by Norwegian Air, so this is not a strictly academic matter.