PSA: Attacking Whille in Bush Reveals You and Everybody in the Bush
I'm not sure where new players would learn this, since I observed this years ago. Maybe Riot can add it as a useful tip at the beginning of games.
I dislike getting paired with teammates that lack fundamental game knowledge like that. And when I do tell them this bit of information, I'm usually met with "stfu." You know, cause trying to keep your teammate from doing a stupid damage trade of half their health for one auto-attack with a bit of helpful game knowledge is an insult to some degree.
W definitely does not visually reveal Jhin if he fires it from the bush.
Q definitely does not visually reveal Blitzcrank until the enemy he pulled actually enters the bush.
E definitely does not visually reveal Rengar if he fires it from the bush.