I went on a taming spree to check, taming every instance of the "Sparkly Brown Dustmoth w/ Orange Glow" colors until they didn't spawn in that color anymore. In total, I tamed;
- 17 Crystalline Dustmoth
- 2
of this version of Underlight Flickerwing
- 7
of this version of the Underlight Flickerwing.
Not a single one had sparkles. The wowhead model viewer shows they should have sparkle, but they definitely don't on live. I also checked
Rockhusk Flickerwing just in case the models got swapped, but no sparkles either. It seems that the sparkle has been lost on that specific moth color. That, or the sparkle ingame is so incredibly hard to see that it's just really easy to miss.
Wouldn't be the first time a texture has been messed up on a Dragonflight mob though (cough cough that one lava spider that's almost pitch black due to missing textures).

Resident exploiter/bug finder that is currently looking for a bug that can safely be shared to tame unintended pets.
Someone is salty and got two of the things I wanted to share fixed.
For proof that I'm not making things up, feel free to look at my Blusky account; @campaigner.bsky.social