Traits don't do much other than switching up your class mechanics/rotation every 5-10 levels.

Almost like the new job abilities did.

Cross Class is likely something they want phased out since they've had no semblance of supporting them outside of tweaking how strong they were (In which they made them weaker. Remember when bards could cross into every dps cooldown when they were 20% untraited?)

If anything, traits / cross class would get folded into the base classes and removed entirely. There's already some very obsolete abilities that could stand to get removed, changed, or improved, and rather than clunk it up with traits, you might as well just bake it into the class. The traits themselves serve no purpose than ensuring no other class can use your skills as well as you can. Given how limited the armory choices are once you get your Jerb, traits are fluff at that point.