I'd be amazed if Bari's decrepit stadium gets touched at all. I think Milan, Naples, Rome, Naples and Turin is a fair representation of Italy in terms of geography and population centres.
I'd actually forgotten about the 5 each so that is a fair point, does make it less likely. For me it'd be stupid to not include Turin but we'll see.
as mentioned by baus, our stadium is the only one that already fully complies with the regulations and is an unconditional uefa cat4 stadium
olimpico at roma is another 99% candidate, it can be renovated pretty easily to meet the requirements as per figc plans. uefa reportedly considered it ancient too lol
as for the rest, is a shitshow. maradona is ancient, the city wants to stick with it, adl wants a new stadium, and time is ticking. san siro is also too old, it's basically hopeless, a completely new venue must be built if they want milano to host some matches. as for the rest, friuli is compliant in all aspects but size, other candidates (franchi, san nicola, bentegodi, etc) are in desperate need of renovation and neither of those have approved plans with budgets lol
the cities you mentioned are a fair representation of italy indeed, but they might select other cities where the bureaucracy is less painful to overcome. either way, any involved city should have not only the stadium but also the infrastructure to host 40-60k spectators and everything that comes with it. an airport is a likely requirement. i wouldn't be surprised if they put cagliari, verona, bologna or even bergamo high on that list simply for feasibility reasons