Inter are really shown as the biggest title candidate in the Serie A next season. This must be due to their general success this season. They didn't only qualify for the Champions League finale and fought well against Manchester City. They won two titles such as Coppa Italia and Italian Super Cup. When we look at the whole picture we can see that Inter were really successful this season. They couldn't be competitive enough for the Serie A title maybe but none of the others did something against Napoli's dominance either.
Inter's current look is really convincing for a title rivalry next time indeed. However the transfer moves this summer will also be important. If they lose important players then surely we would see changes in championship odds.
Actually, at least Napoli or Juventus should be the favourite. Juventus hasn't even had such a bad year, but you can feel that 10 points deduction at the end of the season. It was no coincidence that Napoli became champion in this competition last year. In general, Juventus seems to have had 3 less years, but you shouldn't count last year because Napoli was way too good. In the seasons that AC Milan and Inter have become champions, Juventus have simply played badly. But plenty to think about for Allegri in the summer.