Borussia Dortmund player transfers looks to depend on market. They kept Guirassy because no club met their asking price not because they were focused on developing team. This is different from their handling players like Erling Haaland and Jude Bellingham and they were sold because their amazing performances created huge demand and led to very high offers. Dortmund has not signed many new players means they are not trying to rebuild team right now. Instead of this they appear to be operating with business first strategy willing to sell Guirassy if they receive good offer in future.
In the end it looks the same, except that Guirassy hasn't received a high bid from any club interested in signing him, and I'm sure if a certain club wanted Guirassy at Dortmund's asking price, they would also let him go. That's why this team isn't interesting to watch, as they're more focused on turning players into a business to generate huge profits, rather than developing the team to achieve success in every competition they compete in. If Dortmund continues to take this step, I am sure that this team will never be able to achieve success because more and more of the potential young players they have will eventually be sold to other clubs.