Marner is still the same player, but with a different mindset this season, per the coach's preference. There were flashes of the old way in the early goings of the season and when Matthews returned from whatever his issue was, but they have since bought in as we hit 2025. There's not much more lollygagging with the puck in the OZ waiting for a seam play to open up in any phase of the game. They're attacking the net, reloading or retaking pucks, and cramming it back in to the attack. Make every play a rush chance against a discombobulated defense.
I suspect Willy's improvement was the coaching staff throwing up their hands and saying "you're not going to coach this guy to play center or do much else. He's just going to do whatever he sees out there." They double-shifted him on the PP and just let him go.
I don't recall anything productive coming of Willy's double shift PP once the first unit got off the ice, but I also don't recall much production from PP2 either way, aside from them taking more direct plays to the net. The exercise was entirely just to goose his TOI and is probably counter productive because he reserves energy on PP1 to finish the PP2. I do think Willy's jump in production was a result of them no longer looking for Matthews as option 1, 2, and 3 on the power play, and giving him the half wall after shifting Marner to D. He's really the only other player on the team that can match Matthews' offensive toolkit (carrying, passing, shooting, hands in tight).
If a pro scout couldn't see what McMann did in the AHL was very likely to translate in the NHL, I would wonder if he needs to be in another line of work. It was so obvious. I've truly enjoyed seeing McMann succeed in the NHL. But I do not see leaps and bounds of improvement over last season.
McMann looked the same to me as he did last season, but under a system that suited his skillset better, which got him more time with a player that suited his production (Nylander). At this age, McMann is what he is. Similar note for Tavares, coupled with a shooting percentage rebound (he has been working on his three or four shots with greater repetition and detail this season during practices).
Biggest difference for the team overall in personnel improvements is the D and G.