Okay, let's take a step back and think logically for a moment. This is happening. The national federations of the countries that were sent an invitation are on board, otherwise they wouldn't be ready to disclose further details. It'd be pretty stupid of them to say "yeah, this is how we'll do it" and only after then hear for example the Russians say "yeah, nope, won't fly with us".
They can be stupid, but can they really be that stupid? There must be something lost in translation between their actual plans and these premature details we've heard about it this far. So let's try and clear the signal of the noise.
Calling it now:
The tournament proper will comprise only of the top-six invited countries. "Team Leftovers" and "Team YoungGunz" are tacked-on exhibition. The other squads (or maybe just some, but not all) will play against them, but it's all in the name of fun and games. Having just six teams, not eight also synchronizes well with the intent of having the final series a best-of-three.
The format of the tournament proper will be a simple group of six, all teams facing each other once. The best two teams will play in the final series.
The "100% NHL players" does NOT mean that only NA-based players are allowed or that they even must be first-choice. It simply means that every player under contract in the league is available. While building the final teams however, the federations can actually use whoever they prefer, no matter where they play. Because, duh, the league must be aware that they've already invited teams like Finland and Russia that certainly can't fill the "100% NHL" clause no matter what. And why in the F would anybody want to deliberately weaken them by making 'em scrape for players in the minors when they have better guys available in Europe? Besides, it's not like that well is bottomless either, especially for European countries.
It's a tough day for countries like Slovakia and Switzerland who may feel left out, but hey, it's an invitational event. You don't get the slip, what can you do? Also, that "U23 first choice" thing is part of the noise. If they feel like picking, say, MacKinnon for Team Canada proper, of course he gets to play in Team Canada proper. At worst, he'll have to play in two squads, when Team YoungGunz will face some of the top Euro teams in a series of friendlies.
This is what we'll hear on Friday, or at least very close. Book it.