This is also weird from a lore, RP and storytelling perspective because characters are free from game mechanics and it doesn’t make sense an Illidari who learned the way of the Void with Rendorei NPC Lady (forget her name) would just forget or give up their usage of fel, which is just another arsenal in their toolkit.
Frankly, I’m very excited for Devourer and feels like it fits the class fantasy from Alari the Soul Eater, consumption of purple soul fragments and of course all the Void lore elements from TBC (voidwalkers, Solarion, etc) to the actual ethos of the average demon hunter which relies on seeking immense power no matter the cost to keep the darkness at bay.
I just don’t know how the lore will work for a Rendorei DH from a game perspective unless they aren’t given access to the Mardum intro questline. It checks out that they were taught the fel in exchange for them teaching the Illidari about the void.