I have a DD who did French and Italian. Virtually any university will grab you to do Italian. DDs friend did Italian at Bristol with CCC.
We visited Manchester for a post offer day for their MLang course. 4 years or 5 with year abroad. DD, rightly, decided 5 years is far too long and stops you getting on with the rest of your life. We asked if the Masters students got better jobs - they said no. They even said employers didn't know the difference between the BA and the Masters. So, think very carefully before doing more than 4 years. The Italian lecturer told my DD that if she didn't get into her first choice university, they would not care what the grade was in her 3rd A level. Therefore very little difference between Glasgow and Manchester. Neither are best (Oxford) , but neither are they poor!
Most decent degrees are culture, language and literature. No academic degree will be mostly language. To learn the language a bit more deeply, students can go to translation schools in Italy. At a good university, language acquisition is expected but only really kicks in after the year abroad where everyone improves (unless they are Italian in the first place of course). If he has A level Italian, he will have a head start anyway because quite a few students will be ab initio.
Also, do not do a single language if you can avoid it. You won't find many employers who want Italian. They do think more of you if you offer two languages, or something plus Italian. If he wants to teach Italian, or be a translator, great, but Italian on its own is not highly prized - it is just too niche. Therefore try and factor in other modules if possible.
The public Italian Universities are very average. They tend to get students from their local area and all the students know each other from school. Even a university with 88,000 students (Bologna) is not very friendly and is utterly disorganised. It is not like a UK university at all. DD said lectures were characterised by students smoking, snogging or eating - sometimes at the same time). Some students take years to get an undergrad degree in Italy. An advantage of a university in Italy is that it can broaden your academic horizons. They also have thousands of International exchange students, so plenty of international friends if you cannot find Italian ones.
The Erasmus scheme is currently operating, but who knows about the future? Milan got good reports from students in my DDs year. You are able to teach via the British Council (but you may be in a small town with no-one your age around because they are all at university) but getting a standard job was problematic and DDs university did not recommend it in Italy.
Has he got any ideas about what he may want to do post degree? What were the other 3 universities, out of interest?