I didn't like how you could make a three-line pass up the margin just to have a chip and no chase. It's just designed to setup a passive forecheck. Luckily, among forward-thinkers, head manning the puck died in a very public forum (and a very personal one to me) - I point to the 2013 Eastern Conference Final as the final nail in the coffin to head manning the puck. I don't care to ruin my day with the details of that right now...
Now, we're seeing more of the intent of opening up the game and we're see it harnessed. In a couple of instances here (just because it's handy), you can see what the head man guy is doing...he's pushing back the defense to allow for clean entries. You develop speed behind the puck (a largely Soviet concept). Clean entries allow for room high in the offensive zone, space high in the offensive zone allows for cross net-line passes, cross net-line passes lead to offense.
I don't attribute the two-line pass removal to head injuries. I attribute that to the "no touching" rules that we had coming out of the big sleep. If you can't disrupt speed and turn skates and break strides at all, everything turns into a charge. Charges are illegal because players tend to, ya know, die. The game got too fast for its own good too fast. It took about 7 to 10 years for the league to catch up from a talent perspective. So you had the doldrums of this era (around 2009-2014 or so I guess) where just 25-second-men went out there and skated around as fast as they could to destroy instead of create. Now that the message has been passed down to the developmental leagues and youth hockey, you see depth players are able to skate and handle the puck at speed...not just top liners.
Look at the last five years...we're at 2007 levels of scoring, and over. We get 31 shots per game per team on average. And when you adjust for difference of average attempt, that's the most in league history...