>>42483659Tail Glow is called Firefly Light in Japanese.
Fireflies use a chemical reaction called bioluminescence to glow. This isn't only found in fireflies, and is utilized by certain special insects, deep sea creatures (such as Manaphy), and fungi. Had Gamefreak developed the move with more Pokemon in mind other than Volbeat, they probably wouldn't have conned the name specifically for fireflies. The move is less about being a firefly and moreso about bioluminescence. It was just poor planning and hindsight if anything, but Gamefreak decided to roll with it anyway and give it to Manaphy and Xurkitree. That's speculation but it's probable.
If you ask me, the move would be a good fit for Lanturn and Shiinotic, despite the localized name being a poor indicator.
