This is will be too bad for dortmund if it is true, dortmund has always have the nature of selling their best players. They don't care to know if they need this players , them selling their best players is affecting their performance to win trophies.
If that's what they consider, it means that Dortmund doesn't really aim for trophies every season so they are still considering selling their best players to other teams when there are very tempting offers. The point is that Dortmund are only concerned with money for themselves without thinking about the careers of their players. Obviously this is very unfortunate because Dortmund should have kept the best players to win trophies, not just wanting to earn money from selling the best players.
Dortmund's goal was never to become champions of the Bundesliga. They just want to do business and make a lot of money by selling players. If Dortmund's goal was to win the title, they wouldn't have sold Haaland. They would keep Haaland in the team and try to strengthen their squad. But they don't do it. The main player of their squad this season is Sébastien Haller. I think the Dortmund management will make a lot of money by selling Sébastien Haller within the next two seasons.