It's an electoral referendum, nothing of important. The same organizations of the referendum say that it's consultive. We haven't a real electoral campaign for this 3 referendum (Veneto, Lombardia and province of Belluno). Other regions start this process of trattative state-regioni without any referendum (like Emilia Romagna).
The same type of referendum, for the same electoral reason, was proposed in Campania, Piemonte and Liguria. It's just the start of one of the most dirt elector campaign that i never see