What I expected to happen was for the Ocelots to ignore the Chickens, since they weren't in its line of sight.

What did happen is that the Ocelots began to crowd up against the corner wall, attempting to kill the chickens.

To reproduce this AI misbehavior, Make a wall of sorts similar to what is shown in the image, then spawn Chickens on one side, then Ocelots.

This also seem to affect Llamas, and Wolves

Wolves, and Skeletons

Wolves, and Rabbits

Wolves, and Sheep

Villagers, and Zombies

Villagers, and Evokers (Not Vindicators however?)

Iron Golems, and Evokers