Very unlikely, there were a lot of failed attacks in the five years before on high persons in Austria-Hungary, provincial governors and the Hungarian premier Istvan Tisza, which didn’t lead to escalation. Also the attempted murder of Franz Josef in 1882 in Trieste by an Italian nationalist didnt lead to such an escalation. The AH empire would have to look for another excuse to put down Serbia a notch. By then, the international constellation might have changed and produced a different result, a Balkan war or a war with no British and US involvement so strictly speaking no wotld war.