At the time, the Bruins were already the winner of the trade, but with Monday's roster transactions in the league, they're now the clear winners as Bjork was placed on waivers by the Sabres.
Looking at the trade now, it was an absolute steal by the Bruins:
Hall has appeared in 99 games with Boston and has registered 29 goals and 47 assists for 77 points. He also signed a four-year, $24 million extension on July 23rd, 2021.
Lazar (signed with the Vancouver Canucks as UFA) appeared in 87 games with the Bruins and collected 10 goals and 10.
Bjork skated in 73 games for the Sabres and recorded 8 goals and 6 assists, and is most likely heading to the AHL, unless he's claimed.
Buffalo used that 2021 second-round pick to select Aleksandr Kisakov 53rd overall. He appeared in four games with Moscow Dynamo of the KHL last season and recorded zero points. In two games with the Rochester Americans of the AHL this season, he has yet to reach the scoresheet.