The situation might be a little different because they just had a change of coach and some talented players moved to other clubs. Dortmund have to start from scratch this season because the players have to adapt again to the new coach and some of the newly brought in players also need time to adapt to the new atmosphere around them. The increasing competition in the Bundesliga will make it difficult for Dortmund to compete in the top four, Leverkusen is still a candidate for the title this season after achieving great success last season.
Bayern Munich are also starting to build their squad after a less than impressive performance under Tuchel, Stuttgart will also try to provide competition after finishing below Leverkusen last season. The competition in the Bundesliga is getting more interesting after Bayern Munich dominance was broken, now there will be other teams who want to follow in the footsteps of Leverkusen who have just won the Bundesliga. In my opinion, Dortmund still has the capacity to enter the top four, but the chances are very small.
It will not be too difficult for Dortmund to be able to enter the top 4, as it has happened since the past that this team is consistent enough to stay in the top board but they are not competing for the title.
Indeed Dortmund with their new coach will have a little difficulty but I don't think it's excessive.
You know Dortmund is the only team that was competing with Bayern Munich in the Bundesliga despite not winning trophies but it got to a point when they started dropping in performance and one of the reasons why Dortmund have not been winning many trophies is because I feel the club is just in for business of producing and developing young players and later sell them to other European top clubs. Players like Erling Haaland, Ousmane Dembele, and Jude Bellingham are all players that was developed by the club and was later signed to other top clubs and they are doing pretty well in their respective clubs. Dortmund is still very much recognized in the Bundesliga so they will continue to qualify for the champions league even if they miss out in a season they can still qualify again the following season because they have a lot of young players that are developing in the squad.
Leverkusen and Bayern Munich will still be the favorites to win the title this season and I even think the competition this season will be much fiercer because Bayern Munich made many changes in the team.
And overall the competition in the Bundesliga has been quite fierce in the last few seasons we can see that the Bundesliga is getting more competitive.
Just Because Bayern Leverkusen won the Bundesliga last season doesn't make them an automatic competitive team in the German top league because they just came to the limelight of the Bundesliga last season so until they have maintained consistent performance in upcoming seasons, only then we can be able to classify them as one of the strong teams in the German Bundesliga and let us not forget the Performance of Stuttgart last season, any team can take the Bundesliga by surprise this season, just in same way Bayern Leverkusen did last season so it may not be Bayern Munich or Bayern Leverkusen.