Every single projectile that is currently applying vision around itself, applies its vision for a very brief moment at the center of the map upon getting created.

There are no exceptions here. This goes for linear projectiles, as well as tracking projectiles. So the issue lies within CreateLinearProjectile and CreateTrackingProjectile functions, and is not a bug on the abilities themselves.

Affected spells are: Aether Remnant, Arcane Bolt, Ball Lightning, Chain Frost, Chaos Meteor, Concussive Shot, Earthbind, Flamebreak, Fortune's End, Ghostship, Hookshot, Ice Blast, Ice Shards, Illusory Orb, Mortimer Kisses, Multishot, Mystic Snake, Powershot, Rocket Flare, Sacred Arrow, Shadow Poison, Spark Wraith, Spear of Mars, Stifling Dagger, Storm Hammer, Stroke of Fate, The Swarm, Timber Chain, Tornado, Tree Throw, Tree Volley, Venomous Gale, Wave of Terror, and Wild Axes.

Here is a single example.