Manchester City got their first trophy this season, maybe they still have a chance to be the favorites team again in next season, if there are no changes in their squad. But I think they can certainly reach the top 8 or even semi-finals, but also to win again I think it's too early because there are many big clubs who have pocketed tickets for next season. We can't underestimate them either especially Inter, although they unlucky this season but they can reach to the finals, it's a sign of how strong they are this season and maybe next season they can showing more optimal.
For now their is every possibility for them retaining that trophy as their squad is currently the best so far and most big team are currently facing a lot of challenge so this is actually their best time to become champion of Europe twice but like you said it all depends on the squad performance in this new season campaign because a lot of changes I guess would come and most teams would have been familiar with their game style now so they would have deviced a way to stop their deadly counter.