Montreal signed Dobson to an eight-year extension ($9.5 million per year) following the trade ahead of the 2025 NHL Draft, in which the Islanders now possess three picks in the top 17, including the No. 1 overall pick.
Dobson was the 12th overall pick in the 2018 draft and spent six years with the Islanders.
This past season, the veteran defenceman posted 10 goals and 29 assists (39 points) with a -16 +/- in 71 games.
Meanwhile, for the Islanders, the 23-year-old left wing in Heinemen is coming off his rookie season for the Habbs.
In 62 games, Heinemen put up 10 goals and eight assists with an average ice time of 11:24. He then went on to represent Team Sweden at the 2025 World Championship.
While the Habs beef up their defence, the Islanders could look to possibly use the No. 16 and No. 17 picks to move up into the top 10 of the draft.