Here is some information, do with it as you please.
I looked back to see what Joe Thornton weighed when he was drafted. He was a man child at 220 lbs at 18.
What worries me with McQueen is he's 6'5" and not even 200 lbs. I get it, kids are going to put on weight as they mature and learn they need to add to their frame to handle an NHL schedule. Basically he's tall and lanky right now with previous back issues.
Does adding weight to his frame help or harm him long term? You could say, he's probably going to be more durable because he'll have a thicker frame. At the same time, he'd be carrying more weight than he currently does with a history of back trouble.
I'm not saying we should avoid him in the draft but if you look at only his back history and if he's recovered, I think you'd be missing another piece of the puzzle to see if he's got a future in the NHL, let alone one at a high level. Do with this as you will.