IIRC, the summer video program was about picking apart each game, identifying key trends, and using those to refine the details of his overall game going into the season -- it wasn't exclusively about getting the puck on the net. For a guy who now leads the team in some key metrics and is at the top of the league in some others, I'd say that his continuing efforts are being rewarded. And I'd dispute that he's back to "his old game," if by that you mean skating fast without purpose. No player is raising the play of pretty much anyone he plays with by being ineffectual. For the record, here was PM's response to the program:
The addition of watching video in the summer didn't come as a surprise to Paul Maurice, who is well aware Ehlers' dad, Heinz, is the coach of Denmark's national hockey team.
"He may not have had an option with that. It may have been at the dinner table," Maurice joked. "With Nik, he wants to get better and he wants to improve. We felt that happened for him last year. He comes into this league, skates like the wind, can put up points. Then each year - especially in the second half of last year - he started to figure out the Nik Ehlers way to grind.
"So Ehlers and (Adam) Lowry are going to grind in a different way. But each player has to be able to get combative and win battles and win pucks on the wall. For slightly built young players that's an awful big challenge."
I'd say that this quote is pretty telling. Grind, Nik, grind. Lowry can win infinite numbers of puck battles while being a black hole offensively, but Ehlers, who is defensively sound, an elite zone entry and possession player and now the team's best ES scorer, has to skate in straight lines, feed Wheeler the odd easy tap-in and "be combative." That, once again, is the PoMo Problem: have a baseline system, and force your personnel to play it, rather than adapting your system to take advantage of those unique strengths. So everyone grinds, and Lowrys, and is combative, and battles hard, or gets demoted -- except that some of them don't, and anyway we still lose.
Someone was musing weeks ago here that no professional sports org keeps a coach over a star player, but I honestly think there's few if any players the Jets keep over PoMo. Baffling, but there it is.