Seeing Dortmund policies in the transfer window sometimes makes us annoyed, and one of the most annoying of their policies is releasing their players to direct rivals. In many aspects, Bayern is very profitable because they recruited a lot of players from Dortmund, and overall there are many star players who have been released by Dortmund, and they only hope for instant profits.
Dortmund journey to reach the Champions League final last season felt like luck, because they took an easier route than Madrid. Next season, with Nuri Sahin as the new manager, it seems Dortmund will find it difficult to record the same performance. Reus and Hummels are certain to leave Dortmund, and as usual Dortmund management will move to recruit other talented young players.
Regarding Dortmund behaviour for transfer players the owner has been admitted that he says Dortmund is not rich club so if there are any clubs who interested to their players and those clubs will dare to paying with expensive price then Dortmund is willing to sell those players because from these transfers Dortmund can gets a lot of money to managed their financial conditions so that's why we were often to see Dortmund always be selling their potential players to other clubs but Dortmund management is very smart because they can buy young players with cheap price and within years they can sell those players with expensive price and these things were happened plenty
And your opinion about Dortmund journey can reach to Champion League final match of this season is make sense and i think i have to agree with you that they were luck because at that time before reach to the final match Dortmund can beat several strong clubs such as PSG and Atletico Madrid which if we see from the squad these clubs quality is above to Dortmund and for next season i think it's quite hard for Dortmund to repeat their this season achievement especially next season with new format Dortmund potentially will met against several strong teams early at league phase