In our time line, one of the results of the survival of Clement VII and his subsequent reconciliation with Charles V was the marriage of Alessandro de Medici, a nephew of Clement, and Margaret of Austria, a natural daughter of Charles. Later, after the death of Alessandro, Margaret married the Duke of Parma. That second marriage produced Alexander Farnese, who would later lead the forces of Spain in the Netherlands.
Between 1577 and 1587, Farnese conducted a series of successful sieges that returned much of the southern Netherlands, that is, a good part of present day Belgium, to Spanish control. This resulted in the emigration of a substantial portion of the Protestant population of that region to emigrate to other parts of the Netherlands, as well as the immigration of Catholics from places that remained under Protestant control.
So, if Clement VII is killed by the mutineers in 1527, then we have no marriage of Margaret and Alessandro de Medici. Thus, Margaret would not be available for remarriage to the Duke of Parma, and we have no Alexander Farnese. Without Farnese, who owed much of his success to the political skills he learned from his mother, we have no Spanish reconquest of the southern Netherlands. Without the Spanish reconquest of the southern Netherlands, there is no concentration of the Catholic population in the southern Netherlands. Without that concentration, the cultural and demographic conditions needed for the creation of a separate Kingdom of the Belgians never develop, and we enter the twentieth century with a larger, more powerful Kingdom of the Netherlands.