So were Nail Yakupov and Kerby Rychel. They sent Dubois back to round out his game, and it worked out fine, seemed to improve as well.
I would hope that Sillinger would go back and be above a point per game in that league, improve his overall game and get ice time in every situation.
I had to look it up because that didn't sound right, and no, Yakupov wasn't in the CHL at age 16 and Rychel scored 13 pts at that age. Both had big 17 year old seasons (D-1 for them) though.
I didn't point out Sillinger's gaudy 16 year old season as a way of saying out how great he is and how safe he is as a prospect, the point was that if you wanted him to have a season where he played a lot of minutes and scored a lot in junior, well he did that two years ago. And then last year was a romp for Sillinger. Being slightly better than your peers is a great way to develop, being massively better means not having to develop.
As for PLD, there were many complaints about how much worse he was in his D+1 so I'm not sure if it was so great for him to be in junior, not that there was any choice.
Edit: Funny enough both Rychel and Yakupov have been mentioned as examples of guys that got away with things at the junior level. By that I mean they did things that only could work because the competition was weak. In his age group Rychel was a bull on skates, but didn't have much skill. Yakupov was just a buzzsaw, or a buzzing bee if you prefer. I'm not saying that they failed because they stayed in junior, they might not have made it through any path, but it also can't be shown that they would have benefited from being there longer.