I don't think Dortmund will be a fierce competitor in the Bundesliga title race this season, they have undergone a lot of changes and on the other hand Bundesliga teams like Leverkusen, Leipzig and also Bayern have improved much stronger, it is the opposite of Dortmund so I doubt a little that Dortmund will compete fiercely in the title race especially this season they have a new coach of course every new coach needs to adapt in building a team as well as for Dortmund's new coach this season.
Dortmund remains a team that will compete at the top of the standings despite the many changes that have occurred. I think Dortmund still has a strong DNA in the Bundesliga and they will remain a strong competitor with Bayer Munich, Bayer Leverkusen and maybe Leipzig too.