With a year's worth of OHL experience, and being another year older, Nilsen may have a good shot at not only being on the roster, but actually being a player the team needs to depend on in 2016-17.
The D will be really thinning out...Pittman aged-out, Peters gone to the pros, Saarijarvi gone to wherever the Red Wings would rather see him. Henderson will probably be back as an OA. This leaves him, Duchesne and DiCarlo as the major players on the defense.
From what I've seen this year, I really hope that they have enough talent coming in that they don't need to lean too heavily on Nilsen, but I'm not counting out the possibility of THEM needing HIM, not the other way around.