Normal, you can only really hear it with a aftermarket muffler/exhaust and love the way that ZF8 downshifts and sounds like it's rev-matching those downshifts. Obviously not in the traditional sense as in with a clutch and blipping the throttle, but the ZF8 does have a mechanical way to rev-match the downshifts, I believe there is literature on certain Dodge Cars with the ZF8 that mentions rev-match downshifting.
Considering BMW has dropped their own 7-speed DCT on their M-cars for the ZF8, it pretty reinforces how great this line of transmissions are. It's party due to packaging but also the better overall shifting feel at lower speeds while still being fast and capable.