Wraithlords probably don't count on the basis that there's nobody alive inside it, not even in the half-alive space marine dreadnought sense. The pilot is full-on dead and the stone containing their soul gets put in the wraithlord so they can control it. It's more like a giant haunted suit of armour, in my opinion at least

Eldar titans, on the other hand, actually do have living pilots (and often dead co-pilots), so we've still got space elf mechs