February 24, 2023 was a great night for Mike Koster, as he managed to put up four points, and what's more impressive is that he is a defenseman, so having a night like that when you're supposed to be on the blue line is definitely legendary.
Kyle Dubas was the one who drafted both players back when he was GM of the Leafs. Mike Koster was selected in the 5th round at the 2019 NHL Entry Draft, whereas Veeti Miettinen was selected in 2020 during the 6th round.
The Maple Leafs currently have 45 of their 50 contracts signed and have a little over $1.2 million in cap space remaining. GM Brad Treliving may want to keep his options open and allow for some flexibility, which could be why he chose not to sign these two players.
Mike Koster finished last season with two goals and 14 points in 33 games with the University of Minnesota. Veeti Miettinen played in 37 games for St. Cloud State last season and notched 20 goals and 35 points, which was a very solid campaign for him.