Accordingly to this doc :
All filters that are not mentionned in this list are still producing 8-bits results even if your doc is 8/16-bits.
If I want to use for example "Noise > Dust & Scratches / Median" to remove some minor dust on a backdrop, it's obviously adding the "banding effect" even if the document is 16-bits.
Lots of filters deserve to use 16-bits process in my opinion : we start to work with strong machines these days and they can handle 16-bits processing.
Thank you for reading !