They could possibly make One Wolf Pack give a certain amount of stacks (say, 5 for example) or reduce the number of hits on warhorn 4 (while keeping the damage) to reduce synergy with OWP.
Because the old version was useless/annoying in pvp
The new version is also useless but now it is because damage is too low rather than something about the design
Dagger 2 is actually pretty good on Mirage, only Virtuoso uses the new worse version of Dagger 2 (probably because of a bug). Other Mesmer specs still had the original, better version of Dagger 2 in the beta.