Cosmetics and story aren’t meaningless, and of course there can be an upgrade system that doesn’t impact instanced pvp and pve.
However, having abilities that do impact gameplay more directly would increase the importance of the choice. It would be the type of character-defining progression path that WoW has historically toyed with as a concept, but struggled to implement. Like Path of the Titans.
I hope that the devs can make it work this time. Of course it has the advantage to being specific to the expansion.
A lot comes down to how important the abilities are, imho. It can’t be a massive throughput increase, for example, or something that is required for a particular encounter.
But there can be variation in terms of how effective a particular Covenant’s abilities are across different types of content.
That is already the case. I don’t have to reroll Demon Hunter because some groups want Demon Hunters, or because a particular spec is preferred in the meta at the moment.
It’s not reasonable to turn some variation in effectiveness into a punishment, or declaring that the system is forcing players to roll 4 different versions of a class simply because some differences exist.
There is a question of degree. A particular ability might be too good. But there can be some variation.
