Will the Hail of Blades buff make it good on Jhin again?
There was a short time where Hail of Blades was the best rune of Jhin because of a "bug" that made the AS->AD conversion from his passive apply on the first attack while HoB is active, giving him extra poke damage and movement speed basically for free. Once that "bug" was fixed, HoB feel off from Jhin's build almost entirely.
Now that it's getting buffed to 110% attack speed at every level (which equals ~15.5 bonus AD at level 1, up to 38.5 AD at level 18, plus an extra 44% movement speed from his crits at all levels) for two attacks every time he can proc it, will it be worth? Jhin is all about that hit-and-run playstyle, using his high damage autos (well, high-damage everything) to get short, favorable trades, then running away. Disengaging to let HoB become active again is natural for his playstyle.
Compared to before, he'll be getting significantly more AD and movement speed early on. 54% bonus movement speed for 2 seconds on a crit is a lot at level 1. I think HoB is going to be a better option for him when he needs that early-game power and escape and can't afford to stack up Dark Harvest.