That’s a tough question and easier to answer in terms of PvP than PvE. In PvP it should roughly mean that any class can compete with any other class 1v1. Imo some classes will then excel at certain group roles such as tanking or healing and that’s fine. Those role strengths will be their strength in a 1v1. Let’s say a stamina NB faces off against a Stamina DK. At this current time the NB has the advantage. But in reality the DK would be slower and tanker with good resource return while the NB would be fast with good utility and damage but squishier and those skills sets would be evenly matched.
In PvE balance is apparently supposed to mean that every class can thank, heal or dps and that all dps output is the same. That’s a pipe dream imo.
They really do need to balance PvP and PvE separately, but they won’t do that because they don’t want to invest in PvP, nor do they want to can it altogether because of the outcry it would produce. So instead they’re dragging both aspects through the mud in some ways.