I'm not sure what to think about Rihanna taking over the Discworld. As ITL said, the narration is a huge part of the series and that's all Terry. She may end up being very good at it, but I'm hopeful that Terry still has a few novels left in him yet and, more importantly, he's able to get them out.
Well, if it's managing the property vis a vis making it TV series and movies then I think she could be a good custodian because she'd know what works and doesn't with Discworld adaptions.
But I really don't think there should ever be a Discworld novel that isn't by Terry Pratchett, i.e. I hope she'll be more of a Christopher Tolkein (albeit one more in favour of media adaptions) and less of a Brian Herbert.
is something I'm excited about because it's really the best novel series to adapt for television particularly given TV's long dependence on the police procedural. But that casting is gonna be key.
I just can't think of anyone I'd want to see as Cheery Littlebottom, for example, and I love her.