It actually kind of makes sense that Graves stopped smoking if you take a look at the lore.

First, watch this: https://youtu.be/ao8L-0nSYzg

Now, look at this http://lolwp.com/wp-content/uploads/2012/02/Cutthroat-Graves-and-Cutpurse-Twisted-Fate.jpg

What you can see here is Graves in his younger years, back when he was partnering up with TF and stealing shit and having a blast doing that. As you can see, he isn't smoking - he has no reason to, his life is exciting and fun and he's connected with TF so his social situation is fine as well.

Well, in the process of having fun and stealing shit, Graves got caught and put into one of the worst prisons in Noxus. He also not only lost his partner, it also seemed a lot like he was sold out by TF. So basically sitting in the worst prison in all of Runeterra for a decade with nothing but revenge in his mind, not having anyone to connect to and basically having a really shitty life, what did he do? He started smoking of course, to cope with it. And don't give me the "he wouldn't be able to get cigs in prison" bullshit, in every prison there are corrupt guards who will give them to you for favors and who will smuggle them in. In this period of time, his old splash art with the cigarette makes sense.

Later though, after he got out and after he got himself a shiny new shotgun, he met TF again in Bilgewater during the whole "Burning Tides" event. Initially he wanted to kill TF but shit got complicated, they got caught by GP, then it was MF's plan all along to kill GP to get her own revenge and blow his ship up and to ceize power of bilgewater and that she set this whole thing up, then GP didn't die after all.

ANYWAY, when TF and Graves met again they sorted things out and TF told Graves that in fact, the whole TF-sold-Graves-out-thing isn't actually true and that there was no other way. Together they cooperated to get off GP's ship and to steal shit together again, like in the old times.

So now that Graves got his life sorted out again, now that he can connect with TF again and now that life is fun again, what does he do? He quits smoking of course. He has no reason to do it anymore. So after the Burning Tides event happened, there is also no reason for him to smoke in his splash art or in the game. Yay.

Can we kill this stupid meme now? It's gotten worse than "Better nerf Irelia" at this point.