On top of her long range and wide array of defensive utility, Lux was also among the fastest ranged champions in the game. These changes force Lux to be more mindful of her timing and positioning as opponents now have more opportunities to capitalize on her mistakes.
Base Movement Speed reduced to 330 from 340 Final Spark Cooldown increased to 80/65/50 seconds from 80/60/40
From: ThreshTheDBag | #002
Dark Binding Mana cost reduced to 50/60/70/80/90 from 60/75/90/105/120 Soul Shackles Mana cost reduced to 100 at all ranks from 100/150/200
Harrier Valor now marks targets slightly more frequently Targets are now marked more immediately when Valor lands on the target Vault Quinn now lands closer to her target when using Vault from far away
This changes nothing because Quinn's main issue isn't how frequently Valor marks targets or if her vault places her close enough to the enemies.
Quinn will remain bottom tier adc untill they buff her range, when you have a 650 range Caitlyn and a 525 range Quinn there's no competition, also her ult needs some serious cd reduction.