The next release will be sometime around Jan 2 :D (and will be called the December 2024 release). The releases appear on SubscribeStar around the last day of the month, hence the naming being a month behind.
There will be quite a few additional attacks for Onyx! We've posted concepts for some of the combos / combo finishers / specials in the past ^-^. Currently the animator that will be handling the next Onyx iteration is working on the next boss and some additional enemies, then will be working on her moves.