Wizz Air is doing fine as a company; not on the brink of bankruptcy or about to shut down. Their schedules can be volatile, so perhaps you are right to be concerned about that specific flight operating. All you can do is phone them. I fly them about once a year, and know their CEO (who is a great guy). They just started a big airfare sale, so will be in business for at least another month. Wizz actually has one of the better LCC business models and has a good chance of actually surviving, but it is touch and go.