This trade actually does work because the Celtics have a 27.7 million TPE created from the Anfernee Simons trade.

This allows them to Take in Murphy 3 into the TPE, then trade Sam Hauser to the Pelicans into their newly created TPE (value of Trey Murphy 3 contract)

Milwaukee adds Markannen as well as the Utah pick and a future Boston 1st (great return for a guy looking to leave. Lauri gives them an allstar level player who will bring people into the seats, the high Utah pick and Rollins starts setting them up for the future)

Pelicans save a massive amount of money and adds a late 1st round pick. They can continue to restructure that team'

Utah pushed for a playoff contention. Adding Brown to George, Bailey, Jackson Jr and Kessler gives them a tough team

Celtics move Brown for Giannis and bolster the roster with the use of the TPE in Murphy 3. The result is a very strong group that is better prepared to dominate in the playoffs with a starting lineup of White/Murphy3/Tatum/Giannis/Queta or a MLE level center.