This year could be much more difficult for them, that's a fact, strong teams don't always manage to repeat themselves and achieve their goal next year too and this is something that many teams do and understand, so many players leave to go elsewhere.
Replicating the same achievements from last season into this season is certainly difficult, but it doesn't mean it's impossible for the same team. For example, in the Premier League, Manchester City won four consecutive Premier League titles. Meanwhile, in the Champions League during the 2000s, only Real Madrid managed to win the trophy three times in a row. This means that achieving the same achievements is not impossible for those who are capable, and it could also be influenced by the lack of progress of other teams as the season changes.