Has to do with his age and reaching certain things early as possible like arbitration and UFA status is I recall but I can be wrong.
Will be interesting to see him play the rest of the years as he is supposed to join the team this coming week.
ELC term is based on age at the time of signing (using the draft cutoff date of Sept 15)
18-21 - 3 years
22-23 - 2 years
24 plus - 1 year
Harris was born in July 2000, so he is 21, but turning 22 in July so using the Sept 15 date, he counts as being 22 thus only a 2 year elc.
As for arbitration, if he burns this year of his elc, I don't think he will be arbitration eligible as his contract will expire in 2023 and he would not have played enough seasons (4) or be old enough, 24 to qualify for arbitration.
Realistically for Harris, he will burn this year of his elc, but likely spend 22-23 season in the AHL in Laval.
His production at Northeastern is kind of all over the map.
1/3 PPG as a Freshman
2/3 PPG as a Sophomore
PPG as a Junior (playing 19 games and Covid restrictions)
1/2 PPG as a Senior