Why the Chicago Bulls could say yes:
Every Bulls fan is either going to want to keep Zach LaVine or if the team does trade him is going to want to get a big return for him. While that is obviously the ideal situation, not every situation is ideal in the NBA and the Bulls have absolutely zero leverage in this situation.
With LaVine having the freedom to sign anywhere he wants, it is not like the Bulls can hang anything over his head or other team’s heads to get more value. If he was a restricted free agent then Chicago would actually have leverage. He is not. There is no leverage.
NBA teams do not like losing assets for nothing, though. This trade would take LaVine essentially telling the Bulls and other interested teams that he only wants to be a Laker. This would obviously be a risk for LaVine, but as we see every single offseason, the players have more leverage than ever in the NBA and crazy things happen.
The Bulls would be presented with two options. Lose Lavine and essentially sacrifice that salary as they cannot sign a free agent for anywhere close to that number without Bird Rights. Or, give LaVine what he wants and work with the Lakers to loop a third team in to get someone they like in return.
Julius Randle may have had a bad season last year but he is still an all-star-caliber forward who could mesh well with this cohesive group in Chicago. Evan Fournier gives the team shooting depth off-ball as well.
Again, in a perfect world the Bulls get more for LaVine in a sign-and-trade but with literally zero leverage, if LaVine truly wanted to be a Laker then this would be around the best they can get.