Yes, I agree. The concept feels half-baked in many ways. Just removing the vocals, tweaking a couple of things here and there isn't really enough. The best parts of The Fragile Deviations were the new songs, although it was frustrating that not a single one of them was complete with Trent's voice.
With Teeth instrumental sounds only moderately interesting. I'd like to hear new or unreleased music, and alt takes of every track, not just a select few! If [W_T] Deviations happens, it should basically be the Bleedthrough album as @
Leviathant suggested above.
If a Year Zero Deviations is ever released, I'd expect it to be full-on ARG, with audio snippets and hidden stuff all over, more like a sound collage than an album.