The Naxx 25 hunter helmet is currently textured as the Naxx 40 tier helmet - I do not have any tier 3 but I do have the full naxx 25 tier from phase 1. All other Valorous Cryptstalker pieces have their normal texture.
EDIT: After further investigation, this seems to affect Human Hunters.
Draenei, Night Elf & Dwarf seem to be unaffected, have not checked worgen.