I got this wild theory about KZ - CCA actually and why they sounds different, and they're out with new models and PRO lines :
Imagine if KZ were built by like say 3 people founders.. along with time, 1 founder (call it Mr A) would make KZ sounds more balanced to target audiophile. But the other 2 didn't agree with the idea as their signature sounds worked quite well.
then, Mr. A sadly split with other 2 Mr. B and Mr. C and build up the CCA company to make more balance "KZ" product, but he couldn't use KZ name, so instead He went with CCA. Of course he know well all the supplier and every process things.
So Mr. A was quite successful with CCA brand, with his C04,C10 and C16
Looking at Mr.A's CCA success, Mr. B and Mr. C just realize that actually balance signature were well accepted too in the market, so Mr. B and C also want to make something balance now, KZ released the PRO lines, starting with ZSN Pro, then ZS10 pro and AS16 to go head to head with CCA C16.
Mr. A want to try something better, Trying to lead the innovation with A10.
All stories above are fiction, its not real news, just my stupid wild theory