When researching, I found an old thread created in 2011 that clearly describes a champion named Deadeye. I will let you read for yourself, but he is described as an Assassin/Marksmen with a sniper rifle.
Link to thread: http://forums.na.leagueoflegends.com/board/showthread.php?t=769230
Sharjo3 votes...and? This will have no bearing on what this Jhin fellow will be like. Riot doesn't do fan champion concepts. Ever. The naming is completely coincidental and the only link. Do we not remember Dha Ma and how Kindred was nothing like that particular fan concept?
3ofGot40ve2 votesJust a speculation. And if we don't know much about this character anything is a possibility, including an old champion concept. Also, I do not know anything about what Dha Ma is or how it relates to the creation of Kindred 
GreenLore1 votesDha Ma was posted on the boards after kindreds development was already quite far,so dha ma had no impact on kindred.
Dha Mas concept was posted in april,but kindreds design process started already in january.
Doofs1 votesAheeemm.. Echo (Ekko), Bard, Braum (Angus). Riot likes to keep the general concept of their roles, and for Bard almost keeping their kit entirely. How about you be quiet and support people instead of discouraging them..?
DrCyanide2 votesHow about you be quiet and support people instead of discouraging them..?
Riot themselves has discouraged them, specifically stating that they don't draw from these suggestions. They've told you that the champions concepts board only exists for the amusement of your fellow players, nothing more.
Everyone always goes hunting for some obscure concept with a similar name or art suggestion, and with the thousands that are submitted per year they do find vaguely similar concepts... But then the community fails to realize that there are other community concepts that are also similar, sometimes more so than the ones hailed as the "inspiration."
Case and point, "Gnar." When Gnar was announced, a certain fan creation was hailed as the inspiration. It was for a yordle who had snow based abilities. Players like you flocked to it, claiming Riot should give credit. At the same time, someone else pointed out another "Gnar" concept, but this one was ignored by most of the community. Although not a yordle, this badger mutant would transform into a massive monster that would slam enemies around. The kit was far more similar to Gnar's actual kit, but it was ignored. It's worth pointing out that the kits were similar because the thought process of "what makes a satisfying hulking monster?" lead to the same conclusion.
I ask you, how long have people been wanting a champion that acts more like a sniper than Caitlyn? A long time. Inevitably that is something many Rioters have worked on too. Don't jump to the conclusion that the first sniper concept that shares the same name was the inspiration for anything.
Doofs1 votesJesus christ. Calm down. I heavily agree with you but I don't like making people feel down. If OP made this post to create a discussion I feel happy for em, but if they made it to throw around some idea I'd be certainly upset if I were them.
Like holy shit man, I agree with you 100% but I'm only defending the guy here so people don't flame him down to hell.