Patch Notes: "the following abilities no longer trigger their effects at the start position". What?

can somebody please explain this, im confused as hell here. I put the text taken straight from the patch notes on below. I just dont understand what "effects at the start position" means i guess

similar to last patch's bugfix for Malphite, the following abilities no longer trigger their effects at the start position when interacting with displacement spells like Trundle's E - Pillar of Ice. Apologies in advance for the super-dense formatting here:

Ahri's R - Essence Rush, Corki's W - Valkyrie, Fiora's Q - Lunge, Gragas's E - Body Slam, Hecarim's R - Onslaught of Shadows fear, Irelia's Q - Bladesurge, Jarvan IV's E - Demacian Standard/Q - Dragon Strike combo, Jax's Q - Leap Strike, Jayce's Hammer Form Q - To the Skies!, LeBlanc's W - Distortion, Maokai's W - Twisted Advance, Pantheon's W - Aegis of Zeonia, Poppy's E - Heroic Charge wall stun, Quinn's E - Vault, Renekton's E - Slice and Dice, Sejuani's Q - Arctic Assault, Shen's E - Shadow Dash, Shyvana's R - Dragon's Descent, Tryndamere's E - Spinning Slash, Zac's E - Elastic Slingshot