I've seen skating concerns too, but they don't seem like they're legit concerns or like it's an actual problem. It's like "yeah his skating is fine/good enough, but like he's not an elite skater so can he make it?" It reminds me of Chychrun and how people have been watching him so long that they're trying their best to nitpick something that isn't actually a legit concern. Even the offensive concerns are silly imo. Points are mostly a horrible way to grade players (especially defenseman), but we're talking about the guy who on a poor team, 5th in TOI for defenseman scored the most points ever as a U18 in Liiga.
Here is how he matches up to the other Liiga defenseman that were drafted in the first/second/third round since 2017 (all brackets are ranking by team, TOI is only defenseman)(also left out Anttoni Honka because he played for two teams and got lazy):
Kokkonen (84th OA, 2019):
Team Record: 21-27-12
TOI: 17:25 (6th)
PPG: 0.339
CF%: 42.6% (18th)
Offensive Zone Starts %: 40.2% (24th)
Heiskanen (3rd OA, 2017) -
Team Record: 30-25-5
TOI: 18:59 (5th)
PPG: 0.27
CF%: 52.9% (3rd)
OZS%: 51.5% (8th)
Urho Vaakanainen (18th OA, 2017)
Team Record: 37-14-9
TOI: 14:57 (5th)
PPG: 0.146
CF%: 56.3% (T-1st)
OZS%: 57.7% (1st)
Robin Salo [late birthday] (46th OA, 2017):
Team Record: 21-28-11
TOI: 20:23 (2nd)
PPG: 0.296
CF%: 51.9% (8th)
OZS%: 49% (11th)
Ville Heinola (20th OA, 2019)
Team Record: 31-21-8
TOI: 18:54 (3rd)
PPG: 0.412
CF%: 50.8% (14th)
OZS%: 51.3% (18th)
Looks to me like he was trusted by far the most by his coach in the defensive zone, giving him some of the hardest starts on his team (plus by far harder than any other draft eligible defenseman out of Liiga). Although he may have struggled in those minutes with the very bad looking CF%, he played for arguably the worst team (only rivaled by Salo), and we know that the DZS have a large effect on the CF%. Not only that, he only played more minutes/game than Vaakanainen, and came away with the 2nd best PPG. Obviously this isn't enough information to make any real decisions on, but he compares relatively well to all of these defenseman.