I made an infographic (a real one this time) about stealth and vision in League. Hopefully it is informative and gives Riot something to think about.
I also wrote this 20+ page essay about stealth and vision as a companion piece to this infographic. Hopefully it elaborates and illuminates my thinking on the subject and gives Riot food for thought.
Edit: X-Post on Reddit.
Actually True sight icon is still used in ARAM, where you can buy the Oracle's Extract.
Both the infographic and the essay are tremendously good work, and I thank you very much for posting this! I very much agree with what you said: stealth gameplay in League is full of potential, but heavily underdeveloped, and I agree that part of it comes from the MMO design of stealth being implemented purely as invisibility. I also very much agree that vision is similarly not implemented in the most interesting manner: wards are utterly boring, and I feel one of the reasons why there's such a discrepancy across ranked divisions in their usage, and the associated quality of play in the game, isn't so much because people don't know how to use them, as it is that most care so little about them as a gameplay effect that they have to actively remind themselves to ward, as it very much comes across as a chore rather than an interesting activity.
On top of that, though, champion abilities capable of revealing opponents often do so out of convenience, instead of truly contributing vision or detection as a unique, powerful asset, and this I think has led to a fair degree of (ironically) invisible power, where some effects just happen to have an impact cue or reveal attached, and where champions who would normally comes across as vision providers don't really fulfil that theme (Lux, for example, only reveals with her E and ult). Building upon both stealth and vision systems could add a whole new layer of gameplay what would come particularly in handy when designing and balancing assassins.
Really cool and informative post!
To be honest, Riot could easily add True Vision to several abilities .eg. Ashe E, Quinn W.
Would help alleviate some pressure.
This got the thinking, maybe 
should have some sort of audio warning when they are stealthed.
But, nevertheless, you did a very good job on the post. I can imagine League's official social media reposting it, or even having it turned into a poster at Riot's HQ.
[galio-happy]
Regarding the "3 years between Quinn and Ivern", Tahm Kench was released between them, and his Devour reduces enemies' vision (nearsighting them) while... they're inside him. cough.
Neat post! Fun and easy to read. The fact that 
gives true-vision really annoys me given the low cooldown, long range, and fairly long vision duration.
You forgot LB's E in the "abilities true sight" page.
It grants true sight of the target.
's W grants vision briefly before landing and remaining until it is popped or the duration is over! :D
Also 
's W!
Slight nit-picking, but there are a lot of AoE, non directly vision-related abilities that give vision in their AoE. Counting Darius separately just because his AoE happens to be a cone seems a bit arbitrary, especially since it's 99.9% of the time NOT used to get vision.
Also, what do you mean with "capable of stealth gameplay"? For instance, I don't see what Annie or Braum or Draven do in that list. Gut feeling is your definition might be a bit too large to be relevant.
I find the lack of teemo shrooms disgusting
Ashe is capable of "stealth gameplay"
rly makes u think
This seems like a lot of work just to state the obvious or start a semantic debate
Grenade and Turrets if thrown in brush also reveals champs in same brush, also on rare occasions 1 of your 3 turrets online will bug out and keep shooting at an enemy that is left the area or well past its range of fire even if the turret is suppose to be deactivate #Ghost in the Turret.
you shoulda mentioned one thing theres a difference between invis and camo youd be surprised how many people still dont get that their control wards dont reveal the teemo in the bush or akali in shroud
