I think whats Obtena is trying to say is that traders will get be more desired in teams (thus, PvM "buff"). 15% crit chance for whole team and nano help when everyones costs go up are example of things for which I would like trader in my team.
As for soloing aspect... with bigger nanocost on heals, nerf to crat debuffs, more time between fixer HoT ticks, enforcer absorb line cooldown,... everyone is getting nerfed on that part