Yes, but it doesn't slow. So if he's clipping you at the very edge of his initial W you should be able to walk out before the return hits you for a 2nd stack. On top of that the initial W does LESS damage. So it's inefficient for him to use a max range initial W as harass because the most optimal thing to do is to land the return, which against any half brained enemy wouldn't get hit by if he's hitting a max range initial W. Do you understand so far?
Therefore, whenever a Talon throws a W he should be looking to place the target WITHIN the cone so that the enemy simply can't walk out of the return and he can set up his combo. This is more of a quality of life issue than something that is "OP" or exploitable. If you are finding problems with his initial W hitbox then you just don't know how to play against a Talon properly.
The only problem I see from this is if he clips you with the initial W and finishes you off with it. Which probably feels pretty bad, but if you're running around even remotely close to a Talon hovering at ~10% HP you deserve to die anyway.