This wouldn't make much difference to AP TF's, but the new items provide a new outlook for Twisted Fate as an AD champion.
The downside of the changes is that the average Attack Speed per item is being reduced and an AD TF relies heavily on attack speed and procs.
You need 210% Attack Speed to max out on TF currently, which you can achieve with 4 items and Stacked Deck.
With the same items in the PBE environment you can only achieve 195%
The Current Stacked Deck bonus is BONUS ATTACK SPEED: 10 / 15 / 20 / 25 / 30%
Could this possibly be altered to BONUS ATTACK SPEED: 10 / 15 / 20 / 25 / 30% + 25% of your bonus attack speed
This would mean Twisted Fate would need only 3 good attack speed items (+115%) + Stacked Deck (+30%) + Boots (+30%) + the Stacked Deck Bonus (175*0.25 = +58%) to reach 218% AS and max out.
This would provide virtually NO CHANGE to AP Twisted Fate as he rarely itemises for AS but would allow and AD/AS TF to still reach maxed out Attack Speed for the damage procs he relies on.
I know it's not a common build path, but the new items look like they'd be so cool on him, but the AS nerfs overall really bite into his base effectiveness.