It's not a projectile. Learn what projectile means.
Ahem.
"pro·jec·tile /prəˈdʒɛktɪl, -taɪl/ Pronunciation Key - Show Spelled Pronunciation[pruh-jek-til, -tahyl] Pronunciation Key - Show IPA Pronunciation
–noun
1. an object fired from a gun with an explosive propelling charge, such as a bullet, shell, rocket, or grenade.
2. a body projected or impelled forward, as through the air.
–adjective
3. impelling or driving forward, as a force.
4. caused by impulse, as motion.
5. capable of being impelled forward, as a missile.
6. Zoology. protrusile, as the jaws of a fish.
[Origin: 1655–65; < NL, neut. of prōjectilis (adj.) projecting. See project, -ile]
Dictionary.com Unabridged (v 1.1)
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2006."
So yeah it is a projectile just like Link's boomerang is a projectile. I'm not sure Wario can't eat it though apparently he can eat a charge shot from Samus or Lucario's Aura Sphere and he can eat his own bike so he may well be able to eat Falco's reflector though Falco will probably get another one.