You pretty much just contradicted yourself.
And anyway, your arguments from WoW just don't make sense. Most of the homogenization that happened to classes in WoW happened because of PVE, not Arena. If you are mainly a PvE players, and don't like Arena, I can see why you would point fingers at it saying "you messed up my class!", but that doesn't mean it is true. The bottom line is, the classes became fairly homogenized because they took a PvE game and tried to make balanced PvP with it.
This game is a PvP and PvE game from the start, so it is not the same scenario. Balancing for both will certainly be a challenge, but you cant really use WoW as an example. Blizzard =/= ZOS.