It's not unusual for junior kids to suddenly realize their bad habits no longer work in pro hockey.
Lavoie scored 58 goals in 78 games since the start of those playoffs. Something obviously clicked offensively for him. Let's wait to see if something clicks defensively before creating a narrative of work ethic mostly based on one guy's twitter post.
As an offensive player, really the only somewhat consistent threat they have, on a struggling team you're bound to have some iffy moments defensively. Doesn't mean there aren't things to work on, the move from juniors to pro hockey can certainly be a rude awakening for a lot if players, but it's far too soon to tag him with the lazy defensive liability tag just yet. I know most people understand that, problem is that once someone gets that tag it can be difficult to shake since there are always situations to shine a light on, especially for the not overly agile big skating stride guys. Hard to look busy at that size.
This isn't a new issue regarding Lavoie. It's the main reason why he wasn't ranked higher in the 2019 draft. HockeyProspect had his compete level rated as 4 (the absolute lowest on their grading scale) in their 2019 draft guide.
From their scouting report:
"To be at his best, he needs to be more involved in the play and his compete level needs to be upgraded. Lavoie is a bit of wild card in this draft, he has all the talent in the world but his lack of commitment is a concern"
“He has talent but the compete level is not good. “- NHL Scout, December, 2018
“A lot of his skill is individual skill. He doesn't see the ice well and didn't make guys around him better. He isn't good at all defensively but the hope is you could fix that.” - NHL Scout, April 2019
“His defensive game stinks. He’s good with the puck on his tape but even that stuff is all one on one stuff. He doesn't make many plays off the rush or show creativity.” - NHL Scout, April 2019
“He has tools but I don’t like the lack of compete so I'm guessing he’d be gone before I'd be willing to select him. I will give him props for a much stronger second half. All my live viewings were prior to February. I only saw him on video after that.” - HP Scout, Mark Edwards, May 2019
“His Memorial Cup performance was representative of his regular season, a couple of nice flashes here and there but some disappearing acts as well. One of the most frustrating players I have scouted in years. The talent is there but too many question marks come with it.- HP Scout, Jérôme Bérubé, June 2019
“Had two scouts mention him to me as one of their weaker interviews.”- HP Scout, Mark Edwards, June 2019
I'm not holding my breath on him becoming a good player.