I know the Shadowlands features about this new tmog items are pretty vague (feel free to ignore this topic), but for what I saw and understood this “wings” should replace your cape.
Wouldn’t be cooler if they made a new slot for this? I mean, I would love to use a cape and this wings together.
Edit: by “wings” I mean the Necrolords one, attachments might be better.
I must say I am a big fan of unique and different appearances for the “back” slot. Considering so many players hide the cloaks anyway I think this would seem a great way forward rather than creating another slot.