Basically, i involves dialing things back to a situation more akin to the pre-War of Rage, where the werewolves were actually just one more species of Fera. If we're combining CofD and cWoD, it would essentially be that instead of the Forsaken being the premiere shapeshifters who had a Pangaena ancestor, each of the shapeshifting species would have their own Pangaean ancestor, probably each one of those having mated with the moon (or, in some cases, another large spirit, like Helios, or had absolutely different origins, like the Nagah and their River Kings).
It would essentially present a world where all of the shapeshifting species had their own role, including the werewolves, and they (ostensibly) worked together, etc. Think more Hengeyokai from cWoD, basically. You could even do cool things, where the werespiders and wererats are the ones most pushing to erradicate the Azlu and Beshilu because theys ee it, maybe, as their Pangaean ancestors trying to restructure and reform themselves to take vengeance.
It would be larger in scope. Depending on how it's structured, you can have Auspices remain across the species (Rahu, Irraka, etc.) and apply the species themselves as Tribes (doing away with the Tribes per se and, perhaps, instituting the Pure as an interspecies sort of coalition) which is my personal preference, or you could do away with Auspices and keep the Tribes, giving each species a function and having that take over as Auspices (Uratha are warriors! Nagah are assassins! Nuwisha are teachers! Whatever whatever!) You could also keep Auspices AND Tribes but then you have to buckle down and apply the same for each species, which nnnnnnnnnnnnnnngh that's a lot of work. I guess you could use species as a tertiary axis and just give all of them the same Auspice AND Tribe, but that seems strange (though I can see it working fine with some effort).
Regardless, mechanically speaking, the other species would work the same as werewolves, with different bonuses and different natural abilities, lots of customization via Merits (e.g. instead of giving Nagah AGGRAVATED VENOM from the get go, they need to buy up from a slight paralytic agent that barely slows other shapeshifters down, to something that does outright organ damage on contact). I'd probably keep the bonuses for shapeshifting within the same parameters as the Uratha (i.e. in Gauru they have +8 total in Attributes, so everyone would get +8 to distribute, bonuses to senses might be different sesnes but same bonus, and then some judgment calls for specific things).
For species that have very large differences within the species itself (for example, cats, who can range anywhere from 'lynx' to 'tiger' I would probably do something similar to how the Mokolé were handled, with Merits that can adjust forms to suit whatever the player wants to play.
Depending on how you divide them socially, it can create different viewpoints and relationships to spirits, etc.
I'd also probably definitely bring back the Camazotz, because they're my jam.