This has been an issue for me for a while and I've only just gotten around to reporting it.
When I play as Aeon on Drakes Ravine, I only see very limited weapons fire effects. For something like a nuke, I see the scar on the ground, screen shakes and I get a bit of the halo lighting effect, but no mushroom cloud, smoke etc. For simple effects, like Auroras or sniper bots I can see the firing action (turret kicks back) but no shot. This happens for all players from my point of view, but not for others in the game (although those I play with typically don't play Aeon).
All other maps (generalisation, specifically Strip Mine, Setons) work without issue. This has persisted through the last few patches and client updates. I have tried turning graphics to minimum and then back up, no effect.