It's too early to theory craft with any precision right now, without having some hard numbers and game info from an actual playing and testing.
I'll just say that I hope that game keeps new players and veterans at competitive play field in PvP, without much power gap between them. It provides more challenge, more fun PvP engagement, and more fun overall.
Veteran players will indeed have some advantage, some reward for their time investment, but this reward shouldn't come as an advantage in PvP. Advantage in PvE? Sure. And they will have that.
Multiple gear sets and multiple skill decks to be able to engage in so many more PvE encounters a lot more easily than new players that still have to grind out all those options.
But PvP should remain balanced. St least I hope that it will.