Per Kevin O'Conner (The Ringer):
There are rumblings that the Bucks would like to play a more versatile style of defense next season, which raises the question of whether Brook Lopez has a future there. Trading Brook Lopez for Brown is a perfect match of salaries, and then the Raptors could flip Lopez elsewhere. The amount of screening and cutting Brown could do in support of Giannis Antetokounmpo and Damian Lillard would be glorious to watch.
O'Conner's suggestion is that Lopez would go to a 3rd team, like New Orleans, Memphis, even OKC.
BroLo’s contract is expiring at $23M. Still a very good center (top 5 defensive C) who can stretch the floor, block shots, and brings championship experience.
One version could be a 3 team deal: BBrown goes to Milwaukee, and Lopez goes to a contender, who sends contracts + assets to Toronto.
Or a simple BroLo+33 for Brown…and Toronto ships one of Poeltl / Olynyk / BroLo for someone later.