The raising of the loan to 600m euros is apparently to ensure the airline can definitely cover the summer and possibly until the next election. By deferring until after Italy votes, it avoids a piece of national infrastructure becoming a political football
It is in nobody's interest for Alitalia to collapse suddenly - if it's going to be liquidated (and I can see plenty of reason for an eventual liquidation) then much better for there to be some degree of control and predictability not only for the staff but also to ensure passengers can plan suitably rather than transport to/from/in Italy suddenly turning chaotic
I can cerainly understand why in a country which is so dependent on inbound tourism during the summer that the Govt would want Alitalia to survive until the end of October. Presumably Alitalia makes a large operating loss in winter but in summer maybe at least comes close to breaking even.
I can also understand why Rome wants Alitalia in a stable state for a few months so that the administrators have time to perform a full analysis of the company, give time for negotiations on sales of part of the company and allow any potential buyers to perform due diligence on what they are buying,