Yes, of course, when the club is dependent on one player, the risk will go along with it. We haven't seen Manchester City without Haaland at the moment and Pep Guardiola should have anticipated that. Losing one player will certainly hinder, moreover that player becomes an important figure in their attack line. Because when there are no other players in that position, his teammates will definitely do what they usually do when Haaland plays. Guardiola has to prepare for this kind of thing.
I think Pep Guardiola has warned about that especially when Haaland was replaced by Alvarez several times in the last few games. Haaland is an important figure at the moment in Manchester City's attack, but when Pep Guardiola knows he needs rest then he will be substituted too.
Actually I don't think giving Haaland such a high of playtime by playing him in many match would be such a big problem. Haaland has a good physique to recover his physical condition faster, moreover it will also allow him to adapt more quickly to his new team's style of play. I think Pep Guardiola knows when Haaland has to start on the bench and when he has to start in main line up, he knows that I think.