It makes as much as the whole nebulous "talent pool" claim. Now, I don't want that to sound dismissive of greater access to the NHL - it's not. But what matters is the talent itself. Not the source of it.
I think my own point here is that the source of talent, and in particular, the wide range of that source is going to have an instrumental impact on the talent itself.
That's why I keep asking (conversationally, as I know the work needs to be done because no one has the answer right now) - "why do we insist on counting WHA teams along side NHL teams?"
I don't think WHA needs to equal NHL in the conversation of diluting effects, especially when it's in connection to rapid expansion. If we have 6 NHL and 0 WHA in 1966-67, and then we have 18 NHL and 14 WHA in 1974-75, that's a rapid growth in eight years. That doesn't mean we have to view 18 NHL + 14 WHA as equal and just say "32 Pro Teams" and call it a day necessarily. But we also wouldn't just say it's the equivalent of 18 NHL and 0 WHA. We could (theoretically I suppose but probably with some degree of confidence if we did a deep dive of rosters) determine a coefficient to apply towards WHA, even if it's an ultra-conservative WHA = 0.1 NHL, that would still be the equivalent of 18 NHL + 1.4 ("NHL like") = 19.4, which in connection with a discussion of 6 eight years prior gets to the ultimate point about dilution.
We didn't count KHL teams in 2009. They were taking some quality pieces too. They had money.
Yes, there's a bit of a dilutive effect when KHL teams poach a few notable star players, but in a 30 team NHL it's more limited at the time, and in discussion of an era wide comparison, it's not quite the same when the rate of expansion had already rapidly slowed down, and European Leagues (including the KHL predecessor, the RSL) had already existed, they did not just pop up.
But one reason why we didn't see a catastrophic downturn in game play from the last couple years of the O6 era to the first few years of expansion ("DOUBLED!!!") is because of the talent level and the development route.
There is also a big factor in that all the original teams were in one division while the expansion teams were in their own division. So for the most part, teams were playing at their level, and then in crossover play, the original teams would generally pound the crap out of the other division.
The Sponsorship Era - tangled web of intrigue and trickery as it is - proved to be a really useful path to get well-rounded, mature, developed players into the professional circuit.
As that started to get chipped away (not so much '63, but really '66 to '69), the effects started to show shortly thereafter that mini-generation, if you will. Of course, the number of teams continued to climb, fiddling with eligibility ages didn't help either...that's clear.
But the point is, just because some guys from other places came along and took open jobs doesn't mean that we were any better off. It doesn't mean we were worse off, certainly...which isn't the claim.
There are two things going on here. We can say in sponsorship era, the pool of players that came from the traditional paths of Junior-sponsored teams was sufficient and adequate. So when expansion occurs and the WHA pops up, suddenly there aren't enough players and they need to look at other sources. So they say "Swedes, American college players, come on aboard". That doesn't mean those players are suddenly as good there and then as players from the traditional paths, it just means they need to fill more spots. Of course if the alternative is MORE (and inherently lesser) players from the traditional paths (which should happen as well), then the existence of the "other" paths means that in the absence, you have to take lesser players, so the talent pool does help here, because the point being you get a better group of players than you would otherwise.
But if I told you, "hey, Australia has a bunch of players that want to play over here and your team has some open spots..."
What is your response going to be? "Great! Send them over...the talent pool just grew that much more!" ...? No, of course not. You're gonna tell those guys to take a walk, they aren't good enough...
Yes, if NHL teams suddenly said "hey everyone, we now have an outreach mandate, all of you must have 1 Australian player in your lineup every game". That would of course, not help the NHL talent levels. It would actively harm it. However, that is far different from if 1 Australian player per team is generally able to win a spot and essentially boot out the worst guy on every team from the traditional paths, that necessarily means the league's talent has now improved. Lesser players are replaced by better players.
When there were 3x more Russians in the NHL in 1999 (or whatever) than there are now...was it better? And now, it's worse? Of course not. Vladimir Chebaturkin did not improve the league. Pavel Bure did though.
Much of this goes back to the KHL thing from 2009 you described before. Not that it matters, but certainly nowhere near "3x", Russians were 7.5 % of NHL Games Played in 1998-99 and 6.2 % in 2023-24. But that's an aside, Vladimir Chebaturkin isn't the big draw of the NHL by any means. The point of a player like him is that if he's better than a player from the traditional path, then it means a lesser player is replaced with a player that is (even if marginally) better. The margins can add up over time.
And that's the point...what do you have that's actually making the league better? That's the measure. We're talking about, what, 50, 100, 200 people on the entire planet that matter for this discussion...the whole league (vs the population) is a statistical anomaly. Just attack it from the known quantity (the NHL and adjacent) instead of trying to attack it from a place of an impossible-to-define macro 'pool' angle...that's what I'm saying.
I think we can see how a talent pool is necessarily going to improve over time by looking at the NHL player composition as well as the places where those players come from.
If in Year X all players come from Y
In Year X + 10 all players come from Y, U, W, Z...
then there's a few things that could be going on
the players (opportunities) are much larger
the players from Y are getting worse
U, W and Z have stepped up and are able to be more competitive Y
Some combination of things can be going on here. However, looking at "Y" as "Canadian Junior Hockey", I don't think the middle option is very feasible. Junior Hockey still has as many players and in fact the numbers has only increased.
And of course, a point so obvious that it doesn't need to even be mentioned, but is immensely important is that if Canadian NHL Share goes from say 80 % to 40 %, it's not like they're just randomly cutting out the player that "would have" not made the NHL. It's more or less, straight keeping the top half and replacing the bottom half with players that get beat out for jobs by players from elsewhere, who are more or less going to be "randomly distributed" across the league spectrum, in turn pushing some of the "surviving" players down the depth chart.
And if it turns out - after proper evaluation - that 1975 NHL was worse than 1981 NHL, then I'll wear a t-shirt that says that...that's not my feeling right now, but it could be...I just want to get it right. I don't care whose idea it is...
No real comment on 1975 vs. 1981, which is pretty close in time and where "lulls" in good player years could go a long way to explaining which is going to be better more so than a generalized trend of going upward as "player pool" expands, which for reasons I describe above, is to me, very real.