PVP being in FFXIV in arenas and sequestered battlegrounds does not imply there will be any PVP balancing of classes, they may change how certain abilities affect players versus how they work on monsters, but they won't necessarily change classes for PVP because there is PVP. For evidence of this, look at how things like Brenner and Ballista worked in FFXI, try fighting an RDM/NIN as a BLM, or really any other class other than maybe SAM with nutty gear. PVP in FFXI was severely unbalanced, yet existed.