Agreed. Where's Denise and Joseph C. Phillips? 
Denise, from what I recall, has never returned to any of the Cosby stuff like reunions, interviews, photo shoots, etc... I don't think she's ever given a reason, either. As for Joseph, I guess it would be weird to have him there without Denise? Idk. Tbh, I think she kinda weirded out mentally... I don't think she's all there anymore. Changed her name to some odd name (though I'm sure it has meaning). She reminds me a lot of my oldest sister, who weirded out after my nephew passed away.