Jhin's Deadly Flourish passive

Is it intentional that enemies cannot see if they're marked?

Despite how popular he's been lately, it's honestly not something I've noticed until today when I was fleeing on low health and he fired his W at me. I had assumed he was just trying to get a cheap snipe and I was in no position to dodge it (I was running alongside a wall and the only way to dodge would be into the other people chasing me), but I knew it'd survive it (and did)...

But I was snared.

The fact I had no information that I was going to be snared felt really jarring. Especially when it's not the easiest ability to know if it's going to hit you in the first place - since it only hits up to one champion at a time and it's possible it could have been intercepted.

Then in the same game I flashed off of his trap and then maybe a second later I got snared. Not only did I think his trap only applied the mark while inside it, but again I had nothing on me telling me I was going to be snared.