No, Kotkaniemi takes as much blame as anyone for it. Habs lack of development staff played a big role but Kotkaniemi's fatal flaw was a lack of maturity more than anything.
Habs training staff sent him with an offseason training plan that was largely focused on his skating, they suggested he go work on his skating with the same skating coach that his linemate, Armia, uses. Instead, Kotkaniemi chose to bulk up during the offseason and came back larger but with his biggest flaw not adequately worked on. A lot of the reports after that mention him having issues with the coaching staff, from not listening to them fully or not taking them seriously. The Athletic reported that there was issues with Kotkanemi not listening to coaches and smirking during practice, TSN690 reported that there was tension with him not following through with game plans and not playing the forecheck the way he was asked multiple times including in the playoffs. Him being benched in the playoffs, after having 5 pts in 19 games despite being played as a third liner, and then getting entitled brat about it and announcing that had played his last game for the Habs was the kicker.
Claude Julien has said "“Kotkaniemi can become the player that he can become… if he wants to himself”, said Julien. “Everyone was trying to help him, but at some point, even if you help a player, he has to help himself too. Sometimes, it takes 2-3-4 years before a young player becomes mature enough et gets to recognize his own strengths and weaknesses, and work on that. Now, Kotkaniemi must take the next steps to help himself.”
Bergevin has publicly commented on his maturity too.
"KK didn’t show enough growth in his game/maturity issues and we were not confident with matching that offer-sheet."
Habs take a lot of responsibility for players not working out but him and Poehling are 100% on them.
