Malaysia Airlines is going back to Zagreb with a codeshare with Croatia Airlines.
Flights will be on Wednesday, Friday, and Sunday. Flights will continue onto ZRH. Good news for ZAG, they once again have widebody service. I got this info from Croatia Airlines website.
Malaysia Airlines caters to the large Croatian population living in Australia hence they used to fly there and wish to do so again. JAT (Jugoslovenske Aerolinie) and Qantas both used to fly between Belgrade and Sydney/Melbourne - so it does make sense to fill a niche that is currently void and the move is not a 'politically inspired' decision.