The Raptors need to find a way to hold on to Brown going into the 2024-25 season. The resources they would need to divert into finding a player of his caliber and skill set would be so expansive that the franchise might be better served keeping him and letting him gel with the rest of the rotation.
Toronto's plan to rebuild the roster is likely going to look much smoother in their head than it will in practice. Toronto has expressly stated they don't want to tear it all down as they try to rebuild (a wise move considering Barnes will enter his prime soon), trading Brown might be counterintuitive to that goal.
The Toronto Raptors would win more next year with Bruce Brown.
While Brown's value will obviously be higher this year than he would be as an expiring veteran next season, but contenders will still be after him if he puts together another strong season. If Barnes, Barrett, and Quickley take the leaps Toronto wants, Brown off the bench could be a vital cog in their rotation.
Rebuilding might be centered around young players, but they also shouldn't bail on a talented veteran before getting a chance to see how well he can impact his new squad. Moving Brown is a big risk, and rolling a snake eyes could be a major speed bump in their quest to get back to contention.