Is refund possible if I cannot take a (just rebooked) flight because of coronavirus bans? [duplicate]

My wife had a return flight ticket from Seoul to Barcelona via Istanbul at Turkish Airlines for March 6th. We received a mail today (March 2nd) saying please call our Call Center. We called and they said the flight was cancelled. They gave us the options for a refund or change. When asking which changes were possible, they offered the same flight for the 11th of March. I asked if there could be some problem because of the novel coronavirus and they said they had no information. We changed our flight to March 11th, because they said that if the same happened again and it was cancelled again we could get the refund.

Now I've learnt in IATA's list (https://www.iatatravelcentre.com/international-travel-document-news/1580226297.htm, update from March 1st) about Turkish ban of non-turkish nationals who have been to Korea recently. I think it isn't likely this ban will disappear soon (right?) so we're looking for alternatives like flights via Germany or direct flights to Barcelona.

Now I'm worried that if Turkish Airlines actually does their March 11th flight but they don't let any non-turkish nationals on, they may argue that no refund is possible because it's the passenger responsibility to check that they have all the rights to enter the countries for every layover, at the time they get the flight. Are we going to get a refund? I called the Call Center again but they said they had no information about this.

My wife is Korean but she is currently living in the EU. I think they should have known that because of my wife's nationality she was not allowed to travel. The ticket fare was the cheapest, no cancellations allowed. We had booked the 1st flight before the novel coronavirus was discovered.