We can't say much at this point but I'm pretty sure that City won't win it again. They need 1 bad game in knockout stage and they will be out. Going 2years without bad game it's really hard and City does not have legacy of Real M to do that.
What gives you the impression that Manchester City won't be able to accomplish what Real Madrid did by winning the champions league back-to-back by the next season? Manchester City currently possesses the best team that can defeat any opponent. The only thing I am aware of that would prevent Manchester City from winning the Champions League by the next season is if they sold or loaned some of its important players to other teams, or even if some of their players sustained major injuries that would have a negative impact on the team's performance. Apart from that, I don't think anything can stop Manchester City from reclaiming the champions league title.
So far as Manchester City have Pep Guardiola they still have the chance to win the Champions League next season, Pep Guardiola is the main engine box 4 the Victory of Manchester City in Champions League this season. Pep Guardiola is a coach that understands how to win trophies and how to use players to get what he wants. I know Manchester City does not have much experience when it comes to Champions League but they have a coach who is capable of making a squad to be tough to win competition.
Next season Manchester City will still remain one of the best team in the Champions League, but it won't be very easy for them because teams like Bayern Munich and Real Madrid will improve and to do better than what they did in the concluded Champions League. No doubt that Manchester City is a strong team, but it was so possible for them to win the league because of the poor performance of Real Madrid and Bayern Munich.