The goal should be to make the best team for the event, to have a coaching and playing philosphy to perform over the event, making the best team does not mean to bring the best players, as in you can have a team with nice players, but how well do they actually fit, or oldest, generally, just how the players fit into the team puzzle and if they can play the role the coach wants them to, its a tournament, it's short, so the goal should be to try and do the best.
This all sounds nice, perhaps a little cliche, but let's look at the data.
This year, top teams by age (tiebreaker: youngest prospect):
Germany: 3
France: 4
Kazakhstan: 1
Latvia: 2
Hungary: 6
Austria: 5
The year before, top teams by age:
Austria: 5
Germany: 2
Norway: 6
France: 3
Belarus: 1
Kazakhstan: 4
The year before:
Norway: 4
Germany: 5
Austria: 2
Kazakhstan: 3
Latvia: 1
Italy: 6
Even if we go back another year:
Belarus: 1
Italy: 4
Austria: 5
Norway: 2
Slovenia: 6
Latvia: 3
There's absolutely no correlation between having an older team and doing the best. In fact, if we had a metric to factor for skill, I think there's a very strong correlation between being older and underperforming. Germany and France (by some people) were favorites for promotion this year. Austria, Germany, and Norway were considered contenders along with Belarus. Norway and Germany were favorites the year before as well, along with Latvia.
This is less true for Germany than for some of the smaller mid-minors like say France, Austria, Kazakhstan, but it's still true and holds some weight. We don't have classes. We have prospects. The vast majority of the athletes who play in our national teams will not play a substantial amount of senior level hockey in any top tier league. This, not for lack of opportunity but simply because they aren't good enough. The drop-off between say the best 3-4 athletes in each class and the next 3-4 athletes in each class is huge.
When teams commit to making, not a 4 man roster, not an 8 man roster, a 22 man roster mostly out of players from a single birth year, there are going to be a lot of athletes that straight up aren't very good. So it sounds very nice, "oh we'll see how they fit, schemes this, tactics that, maybe he could play this role, maybe we need some effort guys etc." Some of these guys will have wood boards for hands, they have 20/40 vision, and 30 kph shots that will miss the net altogether 2 in 3 times. To keep someone from the top 4 of the next class or even the top 4 of the following class off the roster because of seniority, you're not swapping out a skilled piece for a slightly less skilled piece, you're proverbially exchanging William Nylander with Zach Hyman.