The rules are set for various reasons and they're likely to remain. To further elaborate on the two things you mentioned. First, is not correct. If 1 player is not eligible, he simply isn't eligible, the rest of the team is fine.
Secondly, the amount of games is not insane. All it really is requires for players to be consistent with their team and to avoid 'last days of season' drama with wintrading, exploiting and other things that usually pop around this period. Perhaps, you as a player don't see the larger picture and it might seem unfair that you can't create a team in the last month but we see it from a different perspective.
In the last years, the last months of arena seasons were always the most difficult times to handle due to amount of new teams that pop up, wintrading, exploiting and selling teams, selling boosts and rating. It might be the uncomfortable truth for many but it's what happens, both here and everywhere else, and we always try to fight it. We will not allow people trying to obtain revenue by destroying someone else's experience, last minute wintrading, exploiting and cheating. This is most apparent to us when we host cash tournaments at the end of the seasons, which we will not do this time. Influx of players that do not play or care for Warmane happens and in the end they claim the rewards, more often than not using cheating and other means to accomplish this.
Our arena seasons, tournaments and rewards are intended for our community, the people who care and the people who play.
The rules and rewards for the next season, will be posted immediately as it starts. The reason why it was not posted immediately this season is because we could not decide outright on the rewards and rules that could fit the entire community as the desires and wants of our community members cross expansions are vastly different.