I had a booking MXP-DXB which got at first schedule changes and later on a change of connecting airport SAW to IST.
I called in to switch it to an Open Ticket where the agent at first confirmed only a change in a 30 day window fo free because he saw only the schedule change. I had to explain my different opinion about it because of changed flight numbers (SAW to IST) and insisted on an Open Ticket valid for any date following involuntary change policy. He confirmed the change with superior successfully.
So I am quite happy now with an open EU to Middle East ticket.
Thanks ISTFlyer for all the good and very helpful information!