Okay, so, hear me out.
The current CP changes and all of that would be left alone, right? Not talking about changing that at all. But using that same concept, what if each class had their own unique constellation and for vampires/werewolves/mortal too? Finally, giving vampires and werewolves way to customize their subclass as well as something for those who remain mortal!!
Not to mention this would ALSO fulfill a big gap in class diversity. As I'm not talking about 'oh just some stat boosts' and passives. I'm talking more like, constellations and sub-skill trees that would work similar to how they worked in Skyrim. They could easily use this to fit new abilities into each class as well as new passives.
How would they do this? Well, there's a few ways. They could either make these character or class specific for the account. (So, say if you earn a LOT of xp on your nightblade, then all of your other nightblade characters would get this other form of leveling up.) Or they could simply make it a unique-character bound thing. Or just make it an account bound thing and award one of these special unique points for every 100 CP.
This would be an amazing, AMAZING solve to class diversity and would allow the devs to get real creative with what they'd give each class in these constellation skill trees.
Oh, and they'd only unlock at level 50. So, it could be considered a sort-of prestige-class system. They could even add some neat cosmetic stars in there too that change how certain abilities look.
Best part? If it's coded like the new CP system, they could easily add in a couple stars per class each chapter if they felt like it. That way we'd get a steady flow of new stuff for existing classes, thus expanding how everyone plays.
I'm going to also finish off with mentioning that with this basically every person at level 50 would unlock the current constellations in the rework plus a unique class constellation and the 'mortal' constellation. Then, the mortal one can be swapped out for a vampire or werewolf constellation upon being infected (points spent in it would transfer, etc etc.)