It's eight games. Kadri went long stretches without goals at points the last two years. He's played with Connor Brown, Par Lindholm, and a little with Josh Leivo. He's more of a facilitator on the powerplay, the shooting opportunities go to Tavares and Matthews. His xG total (I'm generally more of a Corsi purist with analytics, but fwiw), is 1.46 at 5on5. So, multiply that by 10.25, because 10.25x8GP=82... well, that's about 15 5on5 goals, which is fine. From 2015-16 to 2017-18, he had 44 goals on 46.33 xGF, so it pretty much works out, if he had 46.33 xGF the last three years, well 1/3 of that is just a little over 15. His individual xG/60 at 5on5 from 2015-16 to 2017-18 is 0.84, and this year it's 0.83. All this really tells you? He's still taking shots/shot attempts, and they're still from around the net. He probably scored a little better than he should have in 2016-17 and 2017-18, and a good chunk less than you should have expected in 2015-16.
He's probably a 25-27 goal scorer as a true talent, but on this three year stretch, had a disaster first year, and a strong last two, but that round 30 goal number blows some minds. Do the math, 81 goals in three years = 27 goals per year. You don't say "well, he'll go on a tear to make up for the first eight games" cuz that's a gambler's fallacy, but the pucks will start going in for him. He still drives play. He has the highest CF% of any Leaf forward despite everyone in the top-six having a linemate who might make the Hall of Fame (this is MIGHT, don't jump down my throat over counting Marleau and Marner, I wouldn't vote Marleau anyway), while he plays with Connor Brown and Par Lindholm. He gets like, decently rough zone starts. I think he's fine, and hey, maybe he'll get lucky when Nylander gets back and he'll have one of him or Kapanen to play with.
Anyway, Kadri will be fine. I actually think the Leafs look like shit early on, and while I think a lot of the "they're not ready!" talk is dumb, it's not the kids holding them back as it's the fact that Zaitsev, Marleau and Hainsey are cooked, and uh okay, one kid, and I love him, but Connor Brown has not looked good since his rookie year. They also have a really predictable game plan that Babcock refuses to fix, and their breakouts lead to a lot of times where Hainsey or Zaitsev have to advance the puck and float it into the neutral zone, and if they don't, whichever of Rielly, Gardiner, or Dermott are with them is trying to break out with two forwards on them. Justin Bourne had a good bit on it in The Athletic during the playoffs. But Kadri'll be fine, even if this is looking like another first round exit if they make the playoffs.