Your forgot France, they played with B/C as well, but keep in mind, some of these new guys in these teams are here to stay, just like Boyer for example. And they will all be part of the new Olympic Cycle and will be fighting for positions.
But here is the problem, not all of these teams are playing 100% in every game. What costed Belgium was only 1 points or even a few sets. They lost in Iran for Iran in 3-2. Iran had to play really hard and give their best to win, and they did that because they were playing at home. But when they went to Poland they only went for tourism. (I`m not just saying this now, look back on pages and see my post during the Iran vs USA game, I posted saying Iran was not even trying to play, they were just letting easy balls go down). Same thing against Poland and against Russia they played with their bench, which means they gave the US,Poland and Russia each a free win. If they had faced Belgium on the road, Belgium would have beaten them, or if they had played with their bench Belgium would have that 1 extra point.
Argentina played awful the 6 games on the road. Dececo only played last 3 games because they were playing at home, and they played great. Yeah they beat in 3-2 on the road, but let`s say they were playing the last round in Brazil for example, then of course Dececo would have not played and Argentina would care less to win that last game, which means Bulgaria could have won and been in the Final 6.
I hate when teams only play their best when they are playing at home. And when on the road they can care less if they win or not.
Very odd tournament indeed, I can't believe USA/Russia B/C squads managed to enter F6 big respect for them but this is saying a lot more about other teams. Belgium, Bulgaria and Poland stayed behind even using the best possible squads. No wonder FIVB is going to change format starting the next season but I doubt it'll bring more excitement.