I can be a Nightblade since birth and wear Umbral Edge despite running Ardent Flame and Earthen Heart skill lines as Subclasses. Why should I, though? The class you select on character creation now has very little relevance beyond being locked into just one(1) skill line. I appreciated the concept of Class Sets in ESO immensely, as it gave some extra flavor and (sometimes) power to the class you chose! Now, with the decision of implementing the Subclass System which devalues class identity in place of chasing min/max efficiency for the hardcore players or cosmetic purposes for the casual audience, why even restrict sets to class anymore?
Class identity is over. You can no longer see lightning on a player and assume they are a Sorcerer. How about we unlock those class sets, eh? The only class that was truly enjoying the IA sets was basically Dragonknight anyways with Pyrebrand which needed to be nerfed due to how fun it was. Guess Dragonknights will just have to live with the sustain nerfs due to Subclassing and having nerfed Pyrebrand as the consolation prize? Since classes no longer have identity we should be able to equip them if we have a Skill Line attributed to them. If not, then unlock them. Post-subclassing, these sets will struggle further to keep up with the usual outlier sets anyways. Its sad to see remnants of effort to flesh out class identity just sort of sit pointlessly.
On the bright side, maybe now we should be allowed the Class Set cosmetic motif styles on all characters?