Ok... Let's have a little discussion shall we?
What has been nerfed?
DFT was nerfed in this patch by quite a bit, this affects a bit MF and Varus and really hurts Jhin's lategame if he goes for lethality because of how his passive works
MF was nerfed, they reduced her Q damage and they removed her bonus damage on it
Varus was nerfed, they nerfed his Q damage and CD
If i'm not mistaken these are the nerf to lethality ADC... But what actually got buffed?
Crit ADCs all across the board... Even crit MF and crit Varus... Why?
With the MF lethality nerfs they actually buffed crit MF because they changed her Q to make it crit if the first hit kills the target and that it actually can crit with crit chance, the best is to build hybrid lethality and crit like Jhin (also Black cleaver is not so viable anymore on MF ADC but can be good on MF supp)
Varus had his Q changed to reduce its cooldown if it blows a stack of his W, so now he has to AA in order to use his kit properly
Then we have the new Warlord's, it's really good actually, it synergizes very well with RFC and Statik's and it's really good for kiting and heals for a lot
The new Bork can actually be really good on crit ADCs over BT, because with Warlord's that heals you for even 50% every 3/4 autos in lategame the 20% lifesteal from BT can be overkill, the 15% from Bork is enough imo but it's situational, the new Bork is also better early game but it scales in the late very well and this helps Kalista and Bork/Triforce builds
Lucian got also buffed, it's more a qol change but I think it will bring him up a bit
And let's not forget that Fervor got buffed a few weeks ago, that helps Lucian, Ezreal and possibly Corki (but not that much because of his nerfs)