The body for Sev is Kit Fisto, ROTS, no?
The dreds on the POTF2 weren't separate sculpts, so while they were maybe cobbled onto a Sora Bulq head (irony is that this Weequay Jedi is more articulated than any of the film ones, hah), the head itself may be a whole new tooling for it to "work". Simply based on previous sculpts is all... Basically a kitbash that is actually newly molded for it to be produced.
It could be that just the dreds got a new mold too though, and are made specifically to fit the Sora head which has a mold. Either way, if this is the kind of Jedi we're getting, that's vastly superior to the first series O66 sets... I'll take these all year long.