Realized I hadn't actually answered on-topic, so here goes.
I think Nylander is a 100% lock to be an NHLer, already next season. I think his floor, barring anything that we can't predict like a career-altering injury, would be a great depth scoring winger. Someone who can put up 50-55 points on a scoring line that is sheltered.
For that to happen, I think we'd have to see a number of things happen. For example, if his added weight made him a bit less elusive leading to some struggles that in turn made him doubt his game. That could set him back enough for this scenario to happen. I don't think that's very likely though.
I think the projection I see is that he becomes a #2C with a terrific transition game and that can put up 1st line numbers. Say 65 points on average. Will likely look the best when put with two-way workhorse, puck retrieving wingers.
I think his ceiling is a 75-80 point #1C with the complete package. Transition game, a good defensive game based on intelligence. I always predict that he'll struggle a bit in match ups, like Tavares who is a beast but struggles notably when on the ice against the best centers in the game.
EDIT1: I'm well aware that a 50-55 point pace would give him 1st line production. When I say things like depth scoring line, I'm talking about ideal usage to get the most out of a player, not a production bracket.
EDIT2: I wonder if the guy who thinks Nylander has awful vision will join us.
No I don't, I just don't like blanket statements that are open ended enough to absolve the person of ever being wrong. To me, its like why even post if you are ultimately saying nothing? I just don't understand it.
Looking back at this, I think I misunderstood the point you made, Mikey. I apologize for that.