It would be too bad for Dortmund because they wouldn't get a replacement immediately as their pattern of play solely depends on Haaland.
They have good scout team and they can find replacement soon. They have preparation with Moukoko and I believe they will buy other youth players and grown them up. They won't bet all in Moukoko.
If Haaland leaves for laliga Real Maldrid, Athletico would be a perfect maytch for his pattern of play perhaps if he should consider the English premier league then Manchester city should just be the abode. PSG is never an option as too many stars dwell in there but they haven't developed a winning formation with all they have
Haaland won't join Manchester United because he will have to share his striker position with Ronaldo. Even Ronaldo won't have too many seasons left but 1 to 3 seasons are too long for waiting with Haaland. He and Mbappe know that it is their time because Messi and Ronaldo gradually step downwards. They are hurry and don't have patience to wait just a couple of seasons.