Whoa whoa whoa, hold on a second
Passive - Whisper THE PRICE OF PERFECTION All bonus attack speed will now be appropriately reduced by attack speed slows (base attack speed remains fixed)
That still leaves Jhin incredibly resistant to attack speed slows. When I read your posts about this change coming, I thought you meant that his AD multiplier would look like this:
#.4 x Crit Chance + .25 x ((Base Attack Speed x ( 1 + Base AS Growth + Bonus AS ) ) x (1 - AS Slow) - ( ( Base AS x ( 1 + Base AS Growth ) / Base AS) + (Per Level Bonus) + 1
This is already pretty resistant to AS debuffs, but the penalty for getting an AS debuff is at least noticeable.
What it actually looks like (if I'm reading that patch note correctly):
#.4 x Crit Chance + .25 x (Bonus AS) x (1- AS Slow) + (Per Level Bonus) + 1
That makes Jhin stupidly resistant to AS debuffs. The numbers for his DPS and 1-auto attack burst damage loss from an attack speed slow compared to a generic ADC with the same items/stats are given in 3 different cases in the spreadsheet below. The "Jhin" column refers to my reading of how Jhin will be in patch 6.4. "vJhin" shows how I think the formula should really look. "cJhin" shows what I expected Jhin to look like in 6.4 before reading the notes.
As you can see, a 50% attack speed slow will only reduce "Jhin"'s AD by 4% in the given example. That's unacceptable, because a normal ADC has their DPS reduced by 50% by a 50% attack speed slow. "cJhin" reduces his AD by a larger amount- 14% - which is at least enough to be noticeable and "okay." "vJhin" adjusts the formula to make his AD multiplier reduced by the same amount as the AS slow, which makes the reduction to his DPS somewhat higher. Why do I feel that's fair? He should be as vulnerable to AS slows as a generic ADC relative to how much benefit each gets from AS buffs. See my response to 67Chrome for details on what I mean by this.
You may protest "but my skills will do less damage with this!" So what? You're already getting the benefit of not being locked into your auto animation as long as a comparable ADC under the circumstances. You may protest "but that's an enormous nerf compared to live!" So what? Balance his kit around it; don't make Jhin a hard counter to all attack speed slows.
Anyway, at the LEAST, the formula should look like the "cJhin" one, rather than the "Jhin" one, because AS slows will be practically useless vs "Jhin."
TL;DR: This change leaves Jhin practically immune to attack speed slows. I've offered 2 ways to fix this.
Here's the calculations and formulas: https://docs.google.com/spreadsheets/d/1HmfeiRv9bONVUsguHU_9RvoJBDZdIxvRQG_YP3BT3lo/edit?usp=sharing
