The only bad thing about the rule change is imo:
* It is annoying for people that made more than 25 characters that they no longer can play those extra characters in their team. Not a huge issue and they can still use those characters for wg weekly quests and things like that.
* The changing of rules means that the rules might get changed further in the future. Same thing with shutting down low population servers also kinda means this. So it kinda says that at any moment multiboxers might no longer be allowed to play their teams anymore, if warmane decides it is no longer worth allowing it. (although I do understand limiting the characters to 25 and also shutting down servers where almost noone play on since it cost money to run them)
The positive things are:
* Less risk of massive multiboxing teams causes lag when they all use abilities at the same time.
* Since there is no cap on amount of players AoE can hit of many spells it makes those spells less ridiculous, would probably be very stupid to have someone multibox 120+ druids and keep 20 Starfall active 100% of the time. Shamans also makes melee useless against them when they can 1 shot any amount of melee that come within close range of them. (I think shamans should still be able to 1 shot any amount of melee with fire nova and if not enough then add thunderstorm and they should be guaranteed to die, but still a little better than before)
* If warmane is being good, then the change should mean that the rule never have to change ever again (unless they decide it is not worth allowing multiboxers which is still a risk, but they won't need to change it because things getting out of hand with too big teams or anything like that).
* No need for people to feel they need to make a bigger team because of other multiboxers. If someone has a 25 man team, then someone made a 40 man team, then the 25 boxer might felt like they needed to go up to 40, then someone goes up to 80...