They will, I had similar cases in the past. I won a case like this when I missed my cruise because Lufthansa was hit by a strike. Also here we have the case that AY is acting grossly negligent by not allowing rebookings even though they are aware of the risk that the flights could be canceled. But as I said, I don't see them making any major cancellations during the course of the day or tomorrow morning. So far, this has always happened at least 24 hours in advance - unless it was really unforeseeable.