I think this is the area that should be focussed on to address the concerns rather than slowing down TouchID which would be a tragedy. It's true that the notifications are all there but I can see how it's far less ergonomic to now have to press the home button tight at the bottom of the device and then immediately go and do stuff right at the top of the device to get the notifications.
The simplest solution might be, as a settable option, where, if there were notifications displaying on the lock screen at the time the phone is unlocked, the swipe-down notification view is automatically displayed after unlock. That way the phone still goes straight to home screen as quickly as possible if there were no notifications but, if there were notifications, then they are right there on screen and dismissing them involves a simple swipe up (as always) which keeps the thumb down at the bottom of the screen where it already was rather than forcing it to go all the way to the top of the screen to swipe down. This seems an entirely workable solution to me.
These reports about TouchID being slower in 9.0.2 are concerning. I always planned to stick with 9.0.1 and jump straight to 9.1. I hope this TouchID lag is a bug that gets fixed in 9.1 and not a deliberate change.